* libc/time/strftime.c: Adapt for dual-purpose use so not only

	defines strftime(), but can also define wcsftime(); add optional
	test package; speed up %Y handling.
	* libc/time/wcsftime.c:  New file, defining wcsftime() (albeit
	indirectly by including strftime.c) and its documentation.
	* libc/time/time.tex:  Enhance tm_isdst explanation, change strftime
	description to match modified description in strftime.c
	* libc/time/Makefile.am:  Add wcsftime.c and wcsftime.def.  Add a rule
	so that wcsftime.o gets rebuilt when strftime changes.
	* libc/time/Makefile.in:  Regenerate.
	* libc/include/wchar.h (wcsftime): Declare.

5 files changed, 756 insertions, 271 deletions

diff --git a/newlib/libc/time/Makefile.am b/newlib/libc/time/Makefile.am
index 7236a0a04..95716315b 100644
--- a/newlib/libc/time/Makefile.am
+++ b/newlib/libc/time/Makefile.am
@@ -24,7 +24,8 @@ LIB_SOURCES = \
 	tzlock.c	\
 	tzset.c		\
 	tzset_r.c	\
-	tzvars.c
+	tzvars.c	\
+	wcsftime.c
 
 libtime_la_LDFLAGS = -Xcompiler -nostdlib
 
@@ -39,8 +40,11 @@ lib_a_CFLAGS = $(AM_CFLAGS)
 noinst_DATA =
 endif # USE_LIBTOOL
 
+# This rule is needed so that wcsftime.o is rebuilt when strftime.c changes.
 include $(srcdir)/../../Makefile.shared
 
+$(lpfx)wcsftime.$(oext): strftime.c
+
 CHEWOUT_FILES = \
 	asctime.def	\
 	clock.def 	\
@@ -52,7 +56,8 @@ CHEWOUT_FILES = \
 	strftime.def	\
 	time.def	\
 	tzlock.def	\
-	tzset.def
+	tzset.def	\
+	wcsftime.def
 
 SUFFIXES = .def
 
diff --git a/newlib/libc/time/Makefile.in b/newlib/libc/time/Makefile.in
index 12d617527..f330f8534 100644
--- a/newlib/libc/time/Makefile.in
+++ b/newlib/libc/time/Makefile.in
@@ -66,7 +66,8 @@ am__objects_1 = lib_a-asctime.$(OBJEXT) lib_a-asctime_r.$(OBJEXT) \
 	lib_a-mktm_r.$(OBJEXT) lib_a-strftime.$(OBJEXT) \
 	lib_a-strptime.$(OBJEXT) lib_a-time.$(OBJEXT) \
 	lib_a-tzlock.$(OBJEXT) lib_a-tzset.$(OBJEXT) \
-	lib_a-tzset_r.$(OBJEXT) lib_a-tzvars.$(OBJEXT)
+	lib_a-tzset_r.$(OBJEXT) lib_a-tzvars.$(OBJEXT) \
+	lib_a-wcsftime.$(OBJEXT)
 @USE_LIBTOOL_FALSE@am_lib_a_OBJECTS = $(am__objects_1)
 lib_a_OBJECTS = $(am_lib_a_OBJECTS)
 LTLIBRARIES = $(noinst_LTLIBRARIES)
@@ -74,7 +75,7 @@ libtime_la_LIBADD =
 am__objects_2 = asctime.lo asctime_r.lo clock.lo ctime.lo ctime_r.lo \
 	difftime.lo gettzinfo.lo gmtime.lo gmtime_r.lo lcltime.lo \
 	lcltime_r.lo mktime.lo mktm_r.lo strftime.lo strptime.lo \
-	time.lo tzlock.lo tzset.lo tzset_r.lo tzvars.lo
+	time.lo tzlock.lo tzset.lo tzset_r.lo tzvars.lo wcsftime.lo
 @USE_LIBTOOL_TRUE@am_libtime_la_OBJECTS = $(am__objects_2)
 libtime_la_OBJECTS = $(am_libtime_la_OBJECTS)
 @USE_LIBTOOL_TRUE@am_libtime_la_rpath =
@@ -283,7 +284,8 @@ LIB_SOURCES = \
 	tzlock.c	\
 	tzset.c		\
 	tzset_r.c	\
-	tzvars.c
+	tzvars.c	\
+	wcsftime.c
 
 libtime_la_LDFLAGS = -Xcompiler -nostdlib
 @USE_LIBTOOL_TRUE@noinst_LTLIBRARIES = libtime.la
@@ -304,7 +306,8 @@ CHEWOUT_FILES = \
 	strftime.def	\
 	time.def	\
 	tzlock.def	\
-	tzset.def
+	tzset.def	\
+	wcsftime.def
 
 SUFFIXES = .def
 CHEW = ../../doc/makedoc -f $(srcdir)/../../doc/doc.str
@@ -497,6 +500,12 @@ lib_a-tzvars.o: tzvars.c
 lib_a-tzvars.obj: tzvars.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-tzvars.obj `if test -f 'tzvars.c'; then $(CYGPATH_W) 'tzvars.c'; else $(CYGPATH_W) '$(srcdir)/tzvars.c'; fi`
 
+lib_a-wcsftime.o: wcsftime.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-wcsftime.o `test -f 'wcsftime.c' || echo '$(srcdir)/'`wcsftime.c
+
+lib_a-wcsftime.obj: wcsftime.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-wcsftime.obj `if test -f 'wcsftime.c'; then $(CYGPATH_W) 'wcsftime.c'; else $(CYGPATH_W) '$(srcdir)/wcsftime.c'; fi`
+
 mostlyclean-libtool:
 	-rm -f *.lo
 
@@ -651,6 +660,9 @@ objectlist.awk.in: $(noinst_LTLIBRARIES)
 	  echo $$i `pwd`/$$i >> objectlist.awk.in ; \
 	done
 
+# This rule is needed so that wcsftime.o is rebuilt when strftime.c changes.
+$(lpfx)wcsftime.$(oext): strftime.c
+
 .c.def:
 	$(CHEW) < $< > $*.def 2> $*.ref
 	touch stmp-def
diff --git a/newlib/libc/time/strftime.c b/newlib/libc/time/strftime.c
index a3fdb745a..88ccf46b5 100644
--- a/newlib/libc/time/strftime.c
+++ b/newlib/libc/time/strftime.c
@@ -1,7 +1,11 @@
+/* NOTE:  This file defines both strftime() and wcsftime().  Take care when
+ * making changes.  See also wcsftime.c, and note the (small) overlap in the
+ * manual description, taking care to edit both as needed.  */
 /*
  * strftime.c
  * Original Author:	G. Haley
  * Additions from:	Eric Blake
+ * Changes to allow dual use as wcstime, also:	Craig Howland
  *
  * Places characters into the array pointed to by s as controlled by the string
  * pointed to by format. If the total number of resulting characters including
@@ -13,7 +17,7 @@
 
 /*
 FUNCTION
-<<strftime>>---flexible calendar time formatter
+<<strftime>>---convert date and time to a formatted string
 
 INDEX
 	strftime
@@ -128,11 +132,11 @@ The count of days in the year, formatted with three digits
 
 o %k
 The hour (on a 24-hour clock), formatted with leading space if single
-digit (from `<<0>>' to `<<23>>'). Non-POSIX extension. [tm_hour]
+digit (from `<<0>>' to `<<23>>'). Non-POSIX extension (c.p. %I). [tm_hour]
 
 o %l
 The hour (on a 12-hour clock), formatted with leading space if single
-digit (from `<<1>>' to `<<12>>'). Non-POSIX extension. [tm_hour]
+digit (from `<<1>>' to `<<12>>'). Non-POSIX extension (c.p. %H). [tm_hour]
 
 o %m
 The month number, formatted with two digits (from `<<01>>' to `<<12>>').
@@ -203,6 +207,7 @@ seconds), equivalent to "%H:%M:%S". [tm_sec, tm_min, tm_hour]
 
 o %y
 The last two digits of the year (from `<<00>>' to `<<99>>'). [tm_year]
+(Implementation interpretation:  always positive, even for negative years.)
 
 o %Y
 The full year, equivalent to <<%C%y>>.  It will always have at least four
@@ -253,22 +258,48 @@ This implementation does not support <<s>> being NULL, nor overlapping
 #include <time.h>
 #include <string.h>
 #include <stdlib.h>
+#include <limits.h>
 #include "local.h"
+ 
+/* Defines to make the file dual use for either strftime() or wcsftime().
+ * To get wcsftime, define MAKE_WCSFTIME.
+ * To get strftime, do not define MAKE_WCSFTIME.
+ * Names are kept friendly to strftime() usage.  The biggest ugliness is the
+ * use of the CQ() macro to make either regular character constants and
+ * string literals or wide-character constants and wide-character-string
+ * literals, as appropriate.  */
+#if !defined(MAKE_WCSFTIME)
+#  define CHAR		char		/* string type basis */
+#  define CQ(a)		a		/* character constant qualifier */
+#  define SFLG				/* %s flag (null for normal char) */
+# else
+#  define strftime	wcsftime	/* Alternate function name */
+#  define CHAR		wchar_t		/* string type basis */
+#  define CQ(a)		L##a		/* character constant qualifier */
+#  define snprintf	swprintf	/* wide-char equivalent function name */
+#  define strncmp	wcsncmp		/* wide-char equivalent function name */
+#  define SFLG		"l"		/* %s flag (l for wide char) */
+#endif  /* MAKE_WCSFTIME */
+
+/* Enforce the coding assumptions that YEAR_BASE is positive.  (%C, %Y, etc.) */
+#if YEAR_BASE < 0
+#  error "YEAR_BASE < 0"
+#endif
 
 static _CONST int dname_len[7] =
 {6, 6, 7, 9, 8, 6, 8};
 
-static _CONST char *_CONST dname[7] =
-{"Sunday", "Monday", "Tuesday", "Wednesday",
- "Thursday", "Friday", "Saturday"};
+static _CONST CHAR *_CONST dname[7] =
+{CQ("Sunday"), CQ("Monday"), CQ("Tuesday"), CQ("Wednesday"),
+ CQ("Thursday"), CQ("Friday"), CQ("Saturday")};
 
 static _CONST int mname_len[12] =
 {7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8};
 
-static _CONST char *_CONST mname[12] =
-{"January", "February", "March", "April",
- "May", "June", "July", "August", "September", "October", "November",
- "December"};
+static _CONST CHAR *_CONST mname[12] =
+{CQ("January"), CQ("February"), CQ("March"), CQ("April"),
+ CQ("May"), CQ("June"), CQ("July"), CQ("August"),
+ CQ("September"), CQ("October"), CQ("November"), CQ("December")};
 
 /* Using the tm_year, tm_wday, and tm_yday components of TIM_P, return
    -1, 0, or 1 as the adjustment to add to the year for the ISO week
@@ -319,9 +350,9 @@ _DEFUN (iso_year_adjust, (tim_p),
 
 size_t
 _DEFUN (strftime, (s, maxsize, format, tim_p),
-	char *s _AND
+	CHAR *s _AND
 	size_t maxsize _AND
-	_CONST char *format _AND
+	_CONST CHAR *format _AND
 	_CONST struct tm *tim_p)
 {
   size_t count = 0;
@@ -329,7 +360,7 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 
   for (;;)
     {
-      while (*format && *format != '%')
+      while (*format && *format != CQ('%'))
 	{
 	  if (count < maxsize - 1)
 	    s[count++] = *format++;
@@ -337,16 +368,16 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 	    return 0;
 	}
 
-      if (*format == '\0')
+      if (*format == CQ('\0'))
 	break;
 
       format++;
-      if (*format == 'E' || *format == 'O')
+      if (*format == CQ('E') || *format == CQ('O'))
 	format++;
 
       switch (*format)
 	{
-	case 'a':
+	case CQ('a'):
 	  for (i = 0; i < 3; i++)
 	    {
 	      if (count < maxsize - 1)
@@ -356,7 +387,7 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 		return 0;
 	    }
 	  break;
-	case 'A':
+	case CQ('A'):
 	  for (i = 0; i < dname_len[tim_p->tm_wday]; i++)
 	    {
 	      if (count < maxsize - 1)
@@ -366,8 +397,8 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 		return 0;
 	    }
 	  break;
-	case 'b':
-	case 'h':
+	case CQ('b'):
+	case CQ('h'):
 	  for (i = 0; i < 3; i++)
 	    {
 	      if (count < maxsize - 1)
@@ -377,7 +408,7 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 		return 0;
 	    }
 	  break;
-	case 'B':
+	case CQ('B'):
 	  for (i = 0; i < mname_len[tim_p->tm_mon]; i++)
 	    {
 	      if (count < maxsize - 1)
@@ -387,18 +418,18 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 		return 0;
 	    }
 	  break;
-	case 'c':
+	case CQ('c'):
 	  {
-	    /* Length is not known because of %C%y, so recurse. */
+	    /* Recurse to avoid need to replicate %Y formation. */
 	    size_t adjust = strftime (&s[count], maxsize - count,
-				      "%a %b %e %H:%M:%S %C%y", tim_p);
+				      CQ("%a %b %e %H:%M:%S %Y"), tim_p);
 	    if (adjust > 0)
 	      count += adjust;
 	    else
 	      return 0;
 	  }
 	  break;
-	case 'C':
+	case CQ('C'):
 	  {
 	    /* Examples of (tm_year + YEAR_BASE) that show how %Y == %C%y
 	       with 32-bit int.
@@ -424,68 +455,57 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 	    int century = tim_p->tm_year >= 0
 	      ? tim_p->tm_year / 100 + YEAR_BASE / 100
 	      : abs (tim_p->tm_year + YEAR_BASE) / 100;
-            count += snprintf (&s[count], maxsize - count, "%s%.*d",
-                               neg ? "-" : "", 2 - neg, century);
+            count += snprintf (&s[count], maxsize - count, CQ("%s%.*d"),
+                               neg ? CQ("-") : CQ(""), 2 - neg, century);
             if (count >= maxsize)
               return 0;
 	  }
 	  break;
-	case 'd':
-	case 'e':
-	  if (count < maxsize - 2)
-	    {
-	      sprintf (&s[count], *format == 'd' ? "%.2d" : "%2d",
-		       tim_p->tm_mday);
-	      count += 2;
-	    }
-	  else
-	    return 0;
+	case CQ('d'):
+	case CQ('e'):
+	  count += snprintf (&s[count], maxsize - count,
+			*format == CQ('d') ? CQ("%.2d") : CQ("%2d"),
+			tim_p->tm_mday);
+	  if (count >= maxsize)  return 0;
 	  break;
-	case 'D':
-	case 'x':
+	case CQ('D'):
+	case CQ('x'):
 	  /* %m/%d/%y */
-	  if (count < maxsize - 8)
-	    {
-	      sprintf (&s[count], "%.2d/%.2d/%.2d",
-		       tim_p->tm_mon + 1, tim_p->tm_mday,
-		       tim_p->tm_year >= 0 ? tim_p->tm_year % 100
-		       : abs (tim_p->tm_year + YEAR_BASE) % 100);
-	      count += 8;
-	    }
-	  else
-	    return 0;
+	  count += snprintf (&s[count], maxsize - count,
+			CQ("%.2d/%.2d/%.2d"),
+			tim_p->tm_mon + 1, tim_p->tm_mday,
+			tim_p->tm_year >= 0 ? tim_p->tm_year % 100
+			: abs (tim_p->tm_year + YEAR_BASE) % 100);
+          if (count >= maxsize)  return 0;
 	  break;
-        case 'F':
-	  {
-	    /* Length is not known because of %C%y, so recurse. */
+	case CQ('F'):
+	  { /* %F is equivalent to "%Y-%m-%d" */
+	    /* Recurse to avoid need to replicate %Y formation. */
 	    size_t adjust = strftime (&s[count], maxsize - count,
-				      "%C%y-%m-%d", tim_p);
+				      CQ("%Y-%m-%d"), tim_p);
 	    if (adjust > 0)
 	      count += adjust;
 	    else
 	      return 0;
 	  }
           break;
-        case 'g':
-	  if (count < maxsize - 2)
-	    {
-	      /* Be careful of both overflow and negative years, thanks to
+	case CQ('g'):
+	  /* Be careful of both overflow and negative years, thanks to
 		 the asymmetric range of years.  */
-	      int adjust = iso_year_adjust (tim_p);
-	      int year = tim_p->tm_year >= 0 ? tim_p->tm_year % 100
+	  {
+	    int adjust = iso_year_adjust (tim_p);
+	    int year = tim_p->tm_year >= 0 ? tim_p->tm_year % 100
 		: abs (tim_p->tm_year + YEAR_BASE) % 100;
-	      if (adjust < 0 && tim_p->tm_year <= -YEAR_BASE)
+	    if (adjust < 0 && tim_p->tm_year <= -YEAR_BASE)
 		adjust = 1;
-	      else if (adjust > 0 && tim_p->tm_year < -YEAR_BASE)
+	    else if (adjust > 0 && tim_p->tm_year < -YEAR_BASE)
 		adjust = -1;
-	      sprintf (&s[count], "%.2d",
+	    count += snprintf (&s[count], maxsize - count, CQ("%.2d"),
 		       ((year + adjust) % 100 + 100) % 100);
-	      count += 2;
-	    }
-	  else
-	    return 0;
+            if (count >= maxsize)  return 0;
+	  }
           break;
-        case 'G':
+	case CQ('G'):
 	  {
 	    /* See the comments for 'C' and 'Y'; this is a variable length
 	       field.  Although there is no requirement for a minimum number
@@ -512,192 +532,128 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 		year = 0;
 		++century;
 	      }
-            count += snprintf (&s[count], maxsize - count, "%s%.*d%.2d",
-                               neg ? "-" : "", 2 - neg, century, year);
+            count += snprintf (&s[count], maxsize - count, CQ("%s%.*d%.2d"),
+                               neg ? CQ("-") : CQ(""), 2 - neg, century, year);
             if (count >= maxsize)
               return 0;
 	  }
           break;
-	case 'H':
-	case 'k':
-	  if (count < maxsize - 2)
-	    {
-	      sprintf (&s[count], *format == 'k' ? "%2d" : "%.2d",
-		       tim_p->tm_hour);
-	      count += 2;
-	    }
-	  else
-	    return 0;
+	case CQ('H'):
+	case CQ('k'):	/* newlib extension */
+	  count += snprintf (&s[count], maxsize - count,
+			*format == CQ('k') ? CQ("%2d") : CQ("%.2d"),
+			tim_p->tm_hour);
+          if (count >= maxsize)  return 0;
 	  break;
-	case 'I':
-	case 'l':
-	  if (count < maxsize - 2)
-	    {
-	      if (tim_p->tm_hour == 0 ||
-		  tim_p->tm_hour == 12)
-		{
-		  s[count++] = '1';
-		  s[count++] = '2';
-		}
-	      else
-		{
-		  sprintf (&s[count], *format == 'I' ? "%.2d" : "%2d",
-			   tim_p->tm_hour % 12);
-		  count += 2;
-		}
-	    }
-	  else
-	    return 0;
+	case CQ('I'):
+	case CQ('l'):	/* newlib extension */
+	  {
+	    register int  h12;
+	    h12 = (tim_p->tm_hour == 0 || tim_p->tm_hour == 12)  ?
+						12  :  tim_p->tm_hour % 12;
+	    count += snprintf (&s[count], maxsize - count,
+			*format == CQ('I') ? CQ("%.2d") : CQ("%2d"),
+			h12);
+	    if (count >= maxsize)  return 0;
+	  }
 	  break;
-	case 'j':
-	  if (count < maxsize - 3)
-	    {
-	      sprintf (&s[count], "%.3d",
-		       tim_p->tm_yday + 1);
-	      count += 3;
-	    }
-	  else
-	    return 0;
+	case CQ('j'):
+	  count += snprintf (&s[count], maxsize - count, CQ("%.3d"),
+			tim_p->tm_yday + 1);
+          if (count >= maxsize)  return 0;
 	  break;
-	case 'm':
-	  if (count < maxsize - 2)
-	    {
-	      sprintf (&s[count], "%.2d",
-		       tim_p->tm_mon + 1);
-	      count += 2;
-	    }
-	  else
-	    return 0;
+	case CQ('m'):
+	  count += snprintf (&s[count], maxsize - count, CQ("%.2d"),
+			tim_p->tm_mon + 1);
+          if (count >= maxsize)  return 0;
 	  break;
-	case 'M':
-	  if (count < maxsize - 2)
-	    {
-	      sprintf (&s[count], "%.2d",
-		       tim_p->tm_min);
-	      count += 2;
-	    }
-	  else
-	    return 0;
+	case CQ('M'):
+	  count += snprintf (&s[count], maxsize - count, CQ("%.2d"),
+			tim_p->tm_min);
+          if (count >= maxsize)  return 0;
 	  break;
-	case 'n':
+	case CQ('n'):
 	  if (count < maxsize - 1)
-	    s[count++] = '\n';
+	    s[count++] = CQ('\n');
 	  else
 	    return 0;
 	  break;
-	case 'p':
-	  if (count < maxsize - 2)
+	case CQ('p'):
+	  if (count < maxsize - 1)
 	    {
 	      if (tim_p->tm_hour < 12)
-		s[count++] = 'A';
+		s[count++] = CQ('A');
 	      else
-		s[count++] = 'P';
-
-	      s[count++] = 'M';
+		s[count++] = CQ('P');
 	    }
-	  else
-	    return 0;
-	  break;
-	case 'r':
-	  if (count < maxsize - 11)
+	  if (count < maxsize - 1)
 	    {
-	      if (tim_p->tm_hour == 0 ||
-		  tim_p->tm_hour == 12)
-		{
-		  s[count++] = '1';
-		  s[count++] = '2';
-		}
-	      else
-		{
-		  sprintf (&s[count], "%.2d", tim_p->tm_hour % 12);
-		  count += 2;
-		}
-	      s[count++] = ':';
-	      sprintf (&s[count], "%.2d",
-		       tim_p->tm_min);
-	      count += 2;
-	      s[count++] = ':';
-	      sprintf (&s[count], "%.2d",
-		       tim_p->tm_sec);
-	      count += 2;
-	      s[count++] = ' ';
-	      if (tim_p->tm_hour < 12)
-		s[count++] = 'A';
-	      else
-		s[count++] = 'P';
-
-	      s[count++] = 'M';
+	      s[count++] = CQ('M');
 	    }
 	  else
 	    return 0;
 	  break;
-        case 'R':
-          if (count < maxsize - 5)
-            {
-              sprintf (&s[count], "%.2d:%.2d", tim_p->tm_hour, tim_p->tm_min);
-              count += 5;
-            }
-          else
-            return 0;
+	case CQ('r'):
+	  {
+	    register int  h12;
+	    h12 = (tim_p->tm_hour == 0 || tim_p->tm_hour == 12)  ?
+						12  :  tim_p->tm_hour % 12;
+	    count += snprintf (&s[count], maxsize - count,
+			CQ("%.2d:%.2d:%.2d %cM"),
+			h12, 
+			tim_p->tm_min,
+			tim_p->tm_sec,
+			(tim_p->tm_hour < 12)  ?  CQ('A') :  CQ('P'));
+	    if (count >= maxsize)  return 0;
+	  }
+	  break;
+	case CQ('R'):
+          count += snprintf (&s[count], maxsize - count, CQ("%.2d:%.2d"),
+			tim_p->tm_hour, tim_p->tm_min);
+          if (count >= maxsize)  return 0;
           break;
-	case 'S':
-	  if (count < maxsize - 2)
-	    {
-	      sprintf (&s[count], "%.2d",
-		       tim_p->tm_sec);
-	      count += 2;
-	    }
-	  else
-	    return 0;
+	case CQ('S'):
+	  count += snprintf (&s[count], maxsize - count, CQ("%.2d"),
+			tim_p->tm_sec);
+          if (count >= maxsize)  return 0;
 	  break;
-	case 't':
+	case CQ('t'):
 	  if (count < maxsize - 1)
-	    s[count++] = '\t';
+	    s[count++] = CQ('\t');
 	  else
 	    return 0;
 	  break;
-        case 'T':
-        case 'X':
-          if (count < maxsize - 8)
-            {
-              sprintf (&s[count], "%.2d:%.2d:%.2d", tim_p->tm_hour,
-                       tim_p->tm_min, tim_p->tm_sec);
-              count += 8;
-            }
-          else
-            return 0;
+	case CQ('T'):
+	case CQ('X'):
+          count += snprintf (&s[count], maxsize - count, CQ("%.2d:%.2d:%.2d"),
+			tim_p->tm_hour, tim_p->tm_min, tim_p->tm_sec);
+          if (count >= maxsize)  return 0;
           break;
-        case 'u':
+	case CQ('u'):
           if (count < maxsize - 1)
             {
               if (tim_p->tm_wday == 0)
-                s[count++] = '7';
+                s[count++] = CQ('7');
               else
-                s[count++] = '0' + tim_p->tm_wday;
+                s[count++] = CQ('0') + tim_p->tm_wday;
             }
           else
             return 0;
           break;
-	case 'U':
-	  if (count < maxsize - 2)
-	    {
-	      sprintf (&s[count], "%.2d",
+	case CQ('U'):
+	  count += snprintf (&s[count], maxsize - count, CQ("%.2d"),
 		       (tim_p->tm_yday + 7 -
 			tim_p->tm_wday) / 7);
-	      count += 2;
-	    }
-	  else
-	    return 0;
+          if (count >= maxsize)  return 0;
 	  break;
-        case 'V':
-	  if (count < maxsize - 2)
-	    {
-	      int adjust = iso_year_adjust (tim_p);
-	      int wday = (tim_p->tm_wday) ? tim_p->tm_wday - 1 : 6;
-	      int week = (tim_p->tm_yday + 10 - wday) / 7;
-	      if (adjust > 0)
+	case CQ('V'):
+	  {
+	    int adjust = iso_year_adjust (tim_p);
+	    int wday = (tim_p->tm_wday) ? tim_p->tm_wday - 1 : 6;
+	    int week = (tim_p->tm_yday + 10 - wday) / 7;
+	    if (adjust > 0)
 		week = 1;
-	      else if (adjust < 0)
+	    else if (adjust < 0)
 		/* Previous year has 53 weeks if current year starts on
 		   Fri, and also if current year starts on Sat and
 		   previous year was leap year.  */
@@ -706,75 +662,69 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 					     + (YEAR_BASE - 1
 						- (tim_p->tm_year < 0
 						   ? 0 : 2000)))));
-	      sprintf (&s[count], "%.2d", week);
-	      count += 2;
-	    }
-	  else
-	    return 0;
+	    count += snprintf (&s[count], maxsize - count, CQ("%.2d"), week);
+            if (count >= maxsize)  return 0;
+	  }
           break;
-	case 'w':
+	case CQ('w'):
 	  if (count < maxsize - 1)
-            s[count++] = '0' + tim_p->tm_wday;
+            s[count++] = CQ('0') + tim_p->tm_wday;
 	  else
 	    return 0;
 	  break;
-	case 'W':
-	  if (count < maxsize - 2)
-	    {
-	      int wday = (tim_p->tm_wday) ? tim_p->tm_wday - 1 : 6;
-	      sprintf (&s[count], "%.2d",
-		       (tim_p->tm_yday + 7 - wday) / 7);
-	      count += 2;
-	    }
-	  else
-	    return 0;
+	case CQ('W'):
+	  {
+	    int wday = (tim_p->tm_wday) ? tim_p->tm_wday - 1 : 6;
+	    count += snprintf (&s[count], maxsize - count, CQ("%.2d"),
+			(tim_p->tm_yday + 7 - wday) / 7);
+            if (count >= maxsize)  return 0;
+	  }
 	  break;
-	case 'y':
-	  if (count < maxsize - 2)
+	case CQ('y'):
 	    {
 	      /* Be careful of both overflow and negative years, thanks to
 		 the asymmetric range of years.  */
 	      int year = tim_p->tm_year >= 0 ? tim_p->tm_year % 100
 		: abs (tim_p->tm_year + YEAR_BASE) % 100;
-	      sprintf (&s[count], "%.2d", year);
-	      count += 2;
+	      count += snprintf (&s[count], maxsize - count, CQ("%.2d"), year);
+              if (count >= maxsize)  return 0;
 	    }
-	  else
-	    return 0;
 	  break;
-	case 'Y':
-	  {
-	    /* Length is not known because of %C%y, so recurse. */
-	    size_t adjust = strftime (&s[count], maxsize - count,
-				      "%C%y", tim_p);
-	    if (adjust > 0)
-	      count += adjust;
-	    else
-	      return 0;
+	case CQ('Y'):
+	  /* An implementation choice is to have %Y match %C%y, so that it
+	   * gives at least 4 digits, with leading zeros as needed.  */
+	  if(tim_p->tm_year <= INT_MAX-YEAR_BASE)  {
+	    /* For normal, non-overflow case.  */
+	    count += snprintf (&s[count], maxsize - count, CQ("%04d"),
+				tim_p->tm_year + YEAR_BASE);
+	  }
+	  else  {
+	    /* int would overflow, so use unsigned instead.  */
+	    register unsigned year;
+	    year = (unsigned) tim_p->tm_year + (unsigned) YEAR_BASE;
+	    count += snprintf (&s[count], maxsize - count, CQ("%04u"),
+				tim_p->tm_year + YEAR_BASE);
 	  }
+          if (count >= maxsize)  return 0;
 	  break;
-        case 'z':
+	case CQ('z'):
           if (tim_p->tm_isdst >= 0)
             {
-	      if (count < maxsize - 5)
-		{
-		  long offset;
-		  __tzinfo_type *tz = __gettzinfo ();
-		  TZ_LOCK;
-		  /* The sign of this is exactly opposite the envvar TZ.  We
-		     could directly use the global _timezone for tm_isdst==0,
-		     but have to use __tzrule for daylight savings.  */
-		  offset = -tz->__tzrule[tim_p->tm_isdst > 0].offset;
-		  TZ_UNLOCK;
-		  sprintf (&s[count], "%+03ld%.2ld", offset / SECSPERHOUR,
-			   labs (offset / SECSPERMIN) % 60L);
-		  count += 5;
-		}
-	      else
-		return 0;
+	      long offset;
+	      __tzinfo_type *tz = __gettzinfo ();
+	      TZ_LOCK;
+	      /* The sign of this is exactly opposite the envvar TZ.  We
+	         could directly use the global _timezone for tm_isdst==0,
+	         but have to use __tzrule for daylight savings.  */
+	      offset = -tz->__tzrule[tim_p->tm_isdst > 0].offset;
+	      TZ_UNLOCK;
+	      count += snprintf (&s[count], maxsize - count, CQ("%+03ld%.2ld"),
+			offset / SECSPERHOUR,
+			labs (offset / SECSPERMIN) % 60L);
+              if (count >= maxsize)  return 0;
             }
           break;
-	case 'Z':
+	case CQ('Z'):
 	  if (tim_p->tm_isdst >= 0)
 	    {
 	      int size;
@@ -793,9 +743,9 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 	      TZ_UNLOCK;
 	    }
 	  break;
-	case '%':
+	case CQ('%'):
 	  if (count < maxsize - 1)
-	    s[count++] = '%';
+	    s[count++] = CQ('%');
 	  else
 	    return 0;
 	  break;
@@ -806,7 +756,459 @@ _DEFUN (strftime, (s, maxsize, format, tim_p),
 	break;
     }
   if (maxsize)
-    s[count] = '\0';
+    s[count] = CQ('\0');
 
   return count;
 }
+ 
+/* The remainder of this file can serve as a regression test.  Compile
+ *  with -D_REGRESSION_TEST.  */
+#if defined(_REGRESSION_TEST)	/* [Test code:  */
+ 
+/* This test code relies on ANSI C features, in particular on the ability
+ * of adjacent strings to be pasted together into one string.  */
+ 
+/* Test output buffer size (should be larger than all expected results) */
+#define OUTSIZE	256
+ 
+struct test {
+	CHAR  *fmt;	/* Testing format */
+	size_t  max;	/* Testing maxsize */
+	size_t	ret;	/* Expected return value */
+	CHAR  *out;	/* Expected output string */
+	};
+struct list {
+	const struct tm  *tms;	/* Time used for these vectors */
+	const struct test *vec;	/* Test vectors */
+	int  cnt;		/* Number of vectors */
+	};
+ 
+const char  TZ[]="TZ=EST5EDT";
+ 
+/* Define list of test inputs and expected outputs, for the given time zone
+ * and time.  */
+const struct tm  tm0 = {
+	/* Tue Dec 30 10:53:47 EST 2008 (time_t=1230648827) */
+	.tm_sec 	= 47,
+	.tm_min 	= 53,
+	.tm_hour	= 9,
+	.tm_mday	= 30,
+	.tm_mon 	= 11,
+	.tm_year	= 108,
+	.tm_wday	= 2,
+	.tm_yday	= 364,
+	.tm_isdst	= 0
+	};
+const struct test  Vec0[] = {
+	/* Testing fields one at a time, expecting to pass, using exact
+	 * allowed length as what is needed.  */
+	/* Using tm0 for time: */
+	#define EXP(s)	sizeof(s)-1, s
+	{ CQ("%a"), 3+1, EXP(CQ("Tue")) },
+	{ CQ("%A"), 7+1, EXP(CQ("Tuesday")) },
+	{ CQ("%b"), 3+1, EXP(CQ("Dec")) },
+	{ CQ("%B"), 8+1, EXP(CQ("December")) },
+	{ CQ("%c"), 24+1, EXP(CQ("Tue Dec 30 09:53:47 2008")) },
+	{ CQ("%C"), 2+1, EXP(CQ("20")) },
+	{ CQ("%d"), 2+1, EXP(CQ("30")) },
+	{ CQ("%D"), 8+1, EXP(CQ("12/30/08")) },
+	{ CQ("%e"), 2+1, EXP(CQ("30")) },
+	{ CQ("%F"), 10+1, EXP(CQ("2008-12-30")) },
+	{ CQ("%g"), 2+1, EXP(CQ("09")) },
+	{ CQ("%G"), 4+1, EXP(CQ("2009")) },
+	{ CQ("%h"), 3+1, EXP(CQ("Dec")) },
+	{ CQ("%H"), 2+1, EXP(CQ("09")) },
+	{ CQ("%I"), 2+1, EXP(CQ("09")) },
+	{ CQ("%j"), 3+1, EXP(CQ("365")) },
+	{ CQ("%k"), 2+1, EXP(CQ(" 9")) },
+	{ CQ("%l"), 2+1, EXP(CQ(" 9")) },
+	{ CQ("%m"), 2+1, EXP(CQ("12")) },
+	{ CQ("%M"), 2+1, EXP(CQ("53")) },
+	{ CQ("%n"), 1+1, EXP(CQ("\n")) },
+	{ CQ("%p"), 2+1, EXP(CQ("AM")) },
+	{ CQ("%r"), 11+1, EXP(CQ("09:53:47 AM")) },
+	{ CQ("%R"), 5+1, EXP(CQ("09:53")) },
+	{ CQ("%S"), 2+1, EXP(CQ("47")) },
+	{ CQ("%t"), 1+1, EXP(CQ("\t")) },
+	{ CQ("%T"), 8+1, EXP(CQ("09:53:47")) },
+	{ CQ("%u"), 1+1, EXP(CQ("2")) },
+	{ CQ("%U"), 2+1, EXP(CQ("52")) },
+	{ CQ("%V"), 2+1, EXP(CQ("01")) },
+	{ CQ("%w"), 1+1, EXP(CQ("2")) },
+	{ CQ("%W"), 2+1, EXP(CQ("52")) },
+	{ CQ("%x"), 8+1, EXP(CQ("12/30/08")) },
+	{ CQ("%X"), 8+1, EXP(CQ("09:53:47")) },
+	{ CQ("%y"), 2+1, EXP(CQ("08")) },
+	{ CQ("%Y"), 4+1, EXP(CQ("2008")) },
+	{ CQ("%z"), 5+1, EXP(CQ("-0500")) },
+	{ CQ("%Z"), 3+1, EXP(CQ("EST")) },
+	{ CQ("%%"), 1+1, EXP(CQ("%")) },
+	#undef EXP
+	};
+/* Define list of test inputs and expected outputs, for the given time zone
+ * and time.  */
+const struct tm  tm1 = {
+	/* Wed Jul  2 23:01:13 EDT 2008 (time_t=1215054073) */
+	.tm_sec 	= 13,
+	.tm_min 	= 1,
+	.tm_hour	= 23,
+	.tm_mday	= 2,
+	.tm_mon 	= 6,
+	.tm_year	= 108,
+	.tm_wday	= 3,
+	.tm_yday	= 183,
+	.tm_isdst	= 1
+	};
+const struct test  Vec1[] = {
+	/* Testing fields one at a time, expecting to pass, using exact
+	 * allowed length as what is needed.  */
+	/* Using tm0 for time: */
+	#define EXP(s)	sizeof(s)-1, s
+	{ CQ("%a"), 3+1, EXP(CQ("Wed")) },
+	{ CQ("%A"), 9+1, EXP(CQ("Wednesday")) },
+	{ CQ("%b"), 3+1, EXP(CQ("Jul")) },
+	{ CQ("%B"), 4+1, EXP(CQ("July")) },
+	{ CQ("%c"), 24+1, EXP(CQ("Wed Jul  2 23:01:13 2008")) },
+	{ CQ("%C"), 2+1, EXP(CQ("20")) },
+	{ CQ("%d"), 2+1, EXP(CQ("02")) },
+	{ CQ("%D"), 8+1, EXP(CQ("07/02/08")) },
+	{ CQ("%e"), 2+1, EXP(CQ(" 2")) },
+	{ CQ("%F"), 10+1, EXP(CQ("2008-07-02")) },
+	{ CQ("%g"), 2+1, EXP(CQ("08")) },
+	{ CQ("%G"), 4+1, EXP(CQ("2008")) },
+	{ CQ("%h"), 3+1, EXP(CQ("Jul")) },
+	{ CQ("%H"), 2+1, EXP(CQ("23")) },
+	{ CQ("%I"), 2+1, EXP(CQ("11")) },
+	{ CQ("%j"), 3+1, EXP(CQ("184")) },
+	{ CQ("%k"), 2+1, EXP(CQ("23")) },
+	{ CQ("%l"), 2+1, EXP(CQ("11")) },
+	{ CQ("%m"), 2+1, EXP(CQ("07")) },
+	{ CQ("%M"), 2+1, EXP(CQ("01")) },
+	{ CQ("%n"), 1+1, EXP(CQ("\n")) },
+	{ CQ("%p"), 2+1, EXP(CQ("PM")) },
+	{ CQ("%r"), 11+1, EXP(CQ("11:01:13 PM")) },
+	{ CQ("%R"), 5+1, EXP(CQ("23:01")) },
+	{ CQ("%S"), 2+1, EXP(CQ("13")) },
+	{ CQ("%t"), 1+1, EXP(CQ("\t")) },
+	{ CQ("%T"), 8+1, EXP(CQ("23:01:13")) },
+	{ CQ("%u"), 1+1, EXP(CQ("3")) },
+	{ CQ("%U"), 2+1, EXP(CQ("26")) },
+	{ CQ("%V"), 2+1, EXP(CQ("27")) },
+	{ CQ("%w"), 1+1, EXP(CQ("3")) },
+	{ CQ("%W"), 2+1, EXP(CQ("26")) },
+	{ CQ("%x"), 8+1, EXP(CQ("07/02/08")) },
+	{ CQ("%X"), 8+1, EXP(CQ("23:01:13")) },
+	{ CQ("%y"), 2+1, EXP(CQ("08")) },
+	{ CQ("%Y"), 4+1, EXP(CQ("2008")) },
+	{ CQ("%z"), 5+1, EXP(CQ("-0400")) },
+	{ CQ("%Z"), 3+1, EXP(CQ("EDT")) },
+	{ CQ("%%"), 1+1, EXP(CQ("%")) },
+	#undef EXP
+	#define VEC(s)	s, sizeof(s), sizeof(s)-1, s
+	#define EXP(s)	sizeof(s), sizeof(s)-1, s
+	{ VEC(CQ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz")) },
+	{ CQ("0123456789%%%h:`~"), EXP(CQ("0123456789%Jul:`~")) },
+	#undef VEC
+	#undef EXP
+	};
+ 
+#if YEAR_BASE == 1900  /* ( */
+/* Checks for very large years.  YEAR_BASE value relied upon so that the
+ * answer strings can be predetermined.
+ * Years more than 4 digits are not mentioned in the standard for %C, so the
+ * test for those cases are based on the design intent (which is to print the
+ * whole number, being the century).  */
+const struct tm  tmyr0 = {
+	/* Wed Jul  2 23:01:13 EDT [HUGE#] */
+	.tm_sec 	= 13,
+	.tm_min 	= 1,
+	.tm_hour	= 23,
+	.tm_mday	= 2,
+	.tm_mon 	= 6,
+	.tm_year	= INT_MAX - YEAR_BASE/2,
+	.tm_wday	= 3,
+	.tm_yday	= 183,
+	.tm_isdst	= 1
+	};
+#if INT_MAX == 32767
+#  define YEAR	CQ("33717")		/* INT_MAX + YEAR_BASE/2 */
+#  define CENT	CQ("337")
+#  define Year	   CQ("17")
+# elif INT_MAX == 2147483647
+#  define YEAR	CQ("2147484597")
+#  define CENT	CQ("21474845")
+#  define Year	        CQ("97")
+# elif INT_MAX == 9223372036854775807
+#  define YEAR	CQ("9223372036854776757")
+#  define CENT	CQ("92233720368547777")
+#  define Year	                 CQ("57")
+# else
+#  error "Unrecognized INT_MAX value:  enhance me to recognize what you have"
+#endif
+const struct test  Vecyr0[] = {
+	/* Testing fields one at a time, expecting to pass, using a larger
+	 * allowed length than what is needed.  */
+	/* Using tmyr0 for time: */
+	#define EXP(s)	sizeof(s)-1, s
+	{ CQ("%C"), OUTSIZE, EXP(CENT) },
+	{ CQ("%c"), OUTSIZE, EXP(CQ("Wed Jul  2 23:01:13 ")YEAR) },
+	{ CQ("%D"), OUTSIZE, EXP(CQ("07/02/")Year) },
+	{ CQ("%F"), OUTSIZE, EXP(YEAR CQ("-07-02")) },
+	{ CQ("%x"), OUTSIZE, EXP(CQ("07/02/")Year) },
+	{ CQ("%y"), OUTSIZE, EXP(Year) },
+	{ CQ("%Y"), OUTSIZE, EXP(YEAR) },
+	#undef EXP
+	};
+#undef YEAR
+#undef CENT
+#undef Year
+/* Checks for very large negative years.  YEAR_BASE value relied upon so that
+ * the answer strings can be predetermined.  */
+const struct tm  tmyr1 = {
+	/* Wed Jul  2 23:01:13 EDT [HUGE#] */
+	.tm_sec 	= 13,
+	.tm_min 	= 1,
+	.tm_hour	= 23,
+	.tm_mday	= 2,
+	.tm_mon 	= 6,
+	.tm_year	= INT_MIN,
+	.tm_wday	= 3,
+	.tm_yday	= 183,
+	.tm_isdst	= 1
+	};
+#if INT_MAX == 32767
+#  define YEAR	CQ("-30868")		/* INT_MIN + YEAR_BASE */
+#  define CENT	CQ("-308")
+#  define Year	    CQ("68")
+# elif INT_MAX == 2147483647
+#  define YEAR	CQ("-2147481748")
+#  define CENT	CQ("-21474817")
+#  define Year	         CQ("48")
+# elif INT_MAX == 9223372036854775807
+#  define YEAR	CQ("-9223372036854773908")
+#  define CENT	CQ("-92233720368547739")
+#  define Year	                  CQ("08")
+# else
+#  error "Unrecognized INT_MAX value:  enhance me to recognize what you have"
+#endif
+const struct test  Vecyr1[] = {
+	/* Testing fields one at a time, expecting to pass, using a larger
+	 * allowed length than what is needed.  */
+	/* Using tmyr1 for time: */
+	#define EXP(s)	sizeof(s)-1, s
+	{ CQ("%C"), OUTSIZE, EXP(CENT) },
+	{ CQ("%c"), OUTSIZE, EXP(CQ("Wed Jul  2 23:01:13 ")YEAR) },
+	{ CQ("%D"), OUTSIZE, EXP(CQ("07/02/")Year) },
+	{ CQ("%F"), OUTSIZE, EXP(YEAR CQ("-07-02")) },
+	{ CQ("%x"), OUTSIZE, EXP(CQ("07/02/")Year) },
+	{ CQ("%y"), OUTSIZE, EXP(Year) },
+	{ CQ("%Y"), OUTSIZE, EXP(YEAR) },
+	#undef EXP
+	};
+#undef YEAR
+#undef CENT
+#undef Year
+#endif /* YEAR_BASE ) */
+ 
+/* Checks for years just over zero (also test for s=60).
+ * Years less than 4 digits are not mentioned for %Y in the standard, so the
+ * test for that case is based on the design intent.  */
+const struct tm  tmyrzp = {
+	/* Wed Jul  2 23:01:60 EDT 0007 */
+	.tm_sec 	= 60,
+	.tm_min 	= 1,
+	.tm_hour	= 23,
+	.tm_mday	= 2,
+	.tm_mon 	= 6,
+	.tm_year	= 7-YEAR_BASE,
+	.tm_wday	= 3,
+	.tm_yday	= 183,
+	.tm_isdst	= 1
+	};
+#define YEAR	CQ("0007")	/* Design intent:  %Y=%C%y */
+#define CENT	CQ("00")
+#define Year	  CQ("07")
+const struct test  Vecyrzp[] = {
+	/* Testing fields one at a time, expecting to pass, using a larger
+	 * allowed length than what is needed.  */
+	/* Using tmyrzp for time: */
+	#define EXP(s)	sizeof(s)-1, s
+	{ CQ("%C"), OUTSIZE, EXP(CENT) },
+	{ CQ("%c"), OUTSIZE, EXP(CQ("Wed Jul  2 23:01:60 ")YEAR) },
+	{ CQ("%D"), OUTSIZE, EXP(CQ("07/02/")Year) },
+	{ CQ("%F"), OUTSIZE, EXP(YEAR CQ("-07-02")) },
+	{ CQ("%x"), OUTSIZE, EXP(CQ("07/02/")Year) },
+	{ CQ("%y"), OUTSIZE, EXP(Year) },
+	{ CQ("%Y"), OUTSIZE, EXP(YEAR) },
+	#undef EXP
+	};
+#undef YEAR
+#undef CENT
+#undef Year
+/* Checks for years just under zero.
+ * Negative years are not handled by the standard, so the vectors here are
+ * verifying the chosen implemtation.  */
+const struct tm  tmyrzn = {
+	/* Wed Jul  2 23:01:00 EDT -004 */
+	.tm_sec 	= 00,
+	.tm_min 	= 1,
+	.tm_hour	= 23,
+	.tm_mday	= 2,
+	.tm_mon 	= 6,
+	.tm_year	= -4-YEAR_BASE,
+	.tm_wday	= 3,
+	.tm_yday	= 183,
+	.tm_isdst	= 1
+	};
+#define YEAR	CQ("-004")
+#define CENT	CQ("-0")
+#define Year	  CQ("04")
+const struct test  Vecyrzn[] = {
+	/* Testing fields one at a time, expecting to pass, using a larger
+	 * allowed length than what is needed.  */
+	/* Using tmyrzn for time: */
+	#define EXP(s)	sizeof(s)-1, s
+	{ CQ("%C"), OUTSIZE, EXP(CENT) },
+	{ CQ("%c"), OUTSIZE, EXP(CQ("Wed Jul  2 23:01:00 ")YEAR) },
+	{ CQ("%D"), OUTSIZE, EXP(CQ("07/02/")Year) },
+	{ CQ("%F"), OUTSIZE, EXP(YEAR CQ("-07-02")) },
+	{ CQ("%x"), OUTSIZE, EXP(CQ("07/02/")Year) },
+	{ CQ("%y"), OUTSIZE, EXP(Year) },
+	{ CQ("%Y"), OUTSIZE, EXP(YEAR) },
+	#undef EXP
+	};
+#undef YEAR
+#undef CENT
+#undef Year
+ 
+const struct list  ListYr[] = {
+	{ &tmyrzp, Vecyrzp, sizeof(Vecyrzp)/sizeof(Vecyrzp[0]) },
+	{ &tmyrzn, Vecyrzn, sizeof(Vecyrzn)/sizeof(Vecyrzn[0]) },
+	#if YEAR_BASE == 1900
+	{ &tmyr0, Vecyr0, sizeof(Vecyr0)/sizeof(Vecyr0[0]) },
+	{ &tmyr1, Vecyr1, sizeof(Vecyr1)/sizeof(Vecyr1[0]) },
+	#endif
+	};
+ 
+ 
+/* List of tests to be run */
+const struct list  List[] = {
+	{ &tm0, Vec0, sizeof(Vec0)/sizeof(Vec0[0]) },
+	{ &tm1, Vec1, sizeof(Vec1)/sizeof(Vec1[0]) },
+	};
+ 
+#if defined(STUB_getenv_r)
+char *
+_getenv_r(struct _reent *p, const char *cp) { return getenv(cp); }
+#endif
+ 
+int
+main(void)
+{
+int  i, l, errr=0, erro=0, tot=0;
+const char  *cp;
+CHAR  out[OUTSIZE];
+size_t  ret;
+ 
+/* Set timezone so that %z and %Z tests come out right */
+cp = TZ;
+if((i=putenv(cp)))  {
+    printf( "putenv(%s) FAILED, ret %d\n", cp, i);
+    return(-1);
+    }
+if(strcmp(getenv("TZ"),strchr(TZ,'=')+1))  {
+    printf( "TZ not set properly in environment\n");
+    return(-2);
+    }
+tzset();
+ 
+#if defined(VERBOSE)
+printf("_timezone=%d, _daylight=%d, _tzname[0]=%s, _tzname[1]=%s\n", _timezone, _daylight, _tzname[0], _tzname[1]);
+{
+long offset;
+__tzinfo_type *tz = __gettzinfo ();
+/* The sign of this is exactly opposite the envvar TZ.  We
+   could directly use the global _timezone for tm_isdst==0,
+   but have to use __tzrule for daylight savings.  */
+printf("tz->__tzrule[0].offset=%d, tz->__tzrule[1].offset=%d\n", tz->__tzrule[0].offset, tz->__tzrule[1].offset);
+}
+#endif
+ 
+/* Run all of the exact-length tests as-given--results should match */
+for(l=0; l<sizeof(List)/sizeof(List[0]); l++)  {
+    const struct list  *test = &List[l];
+    for(i=0; i<test->cnt; i++)  {
+	tot++;	/* Keep track of number of tests */
+	ret = strftime(out, test->vec[i].max, test->vec[i].fmt, test->tms);
+	if(ret != test->vec[i].ret)  {
+	    errr++;
+	    fprintf(stderr,
+		"ERROR:  return %d != %d expected for List[%d].vec[%d]\n",
+						ret, test->vec[i].ret, l, i);
+	    }
+	if(strncmp(out, test->vec[i].out, test->vec[i].max-1))  {
+	    erro++;
+	    fprintf(stderr,
+		"ERROR:  \"%"SFLG"s\" != \"%"SFLG"s\" expected for List[%d].vec[%d]\n",
+						out, test->vec[i].out, l, i);
+	    }
+	}
+    }
+ 
+/* Run all of the exact-length tests with the length made too short--expect to
+ * fail.  */
+for(l=0; l<sizeof(List)/sizeof(List[0]); l++)  {
+    const struct list  *test = &List[l];
+    for(i=0; i<test->cnt; i++)  {
+	tot++;	/* Keep track of number of tests */
+	ret = strftime(out, test->vec[i].max-1, test->vec[i].fmt, test->tms);
+	if(ret != 0)  {
+	    errr++;
+	    fprintf(stderr,
+		"ERROR:  return %d != %d expected for List[%d].vec[%d]\n",
+						ret, 0, l, i);
+	    }
+	/* Almost every conversion puts out as many characters as possible, so
+	 * go ahead and test the output even though have failed.  (The test
+	 * times chosen happen to not hit any of the cases that fail this, so it
+	 * works.)  */
+	if(strncmp(out, test->vec[i].out, test->vec[i].max-1-1))  {
+	    erro++;
+	    fprintf(stderr,
+		"ERROR:  \"%"SFLG"s\" != \"%"SFLG"s\" expected for List[%d].vec[%d]\n",
+						out, test->vec[i].out, l, i);
+	    }
+	}
+    }
+ 
+/* Run all of the special year test cases */
+for(l=0; l<sizeof(ListYr)/sizeof(ListYr[0]); l++)  {
+    const struct list  *test = &ListYr[l];
+    for(i=0; i<test->cnt; i++)  {
+	tot++;	/* Keep track of number of tests */
+	ret = strftime(out, test->vec[i].max, test->vec[i].fmt, test->tms);
+	if(ret != test->vec[i].ret)  {
+	    errr++;
+	    fprintf(stderr,
+		"ERROR:  return %d != %d expected for ListYr[%d].vec[%d]\n",
+						ret, test->vec[i].ret, l, i);
+	    }
+	if(strncmp(out, test->vec[i].out, test->vec[i].max-1))  {
+	    erro++;
+	    fprintf(stderr,
+		"ERROR:  \"%"SFLG"s\" != \"%"SFLG"s\" expected for ListYr[%d].vec[%d]\n",
+						out, test->vec[i].out, l, i);
+	    }
+	}
+    }
+ 
+#define STRIZE(f)	#f
+#define NAME(f)	STRIZE(f)
+printf(NAME(strftime) "() test ");
+if(errr || erro)  printf("FAILED %d/%d of", errr, erro);
+  else    printf("passed");
+printf(" %d test cases.\n", tot);
+ 
+return(errr || erro);
+}
+#endif /* defined(_REGRESSION_TEST) ] */
diff --git a/newlib/libc/time/time.tex b/newlib/libc/time/time.tex
index 4859404a3..cecd0f5f5 100644
--- a/newlib/libc/time/time.tex
+++ b/newlib/libc/time/time.tex
@@ -44,6 +44,8 @@ Number of days elapsed since last January 1, between 0 and 365 inclusive.
 @item tm_isdst
 Daylight Savings Time flag: positive means DST in effect, zero means DST
 not in effect, negative means no information about DST is available.
+Although for mktime(), negative means that it should decide if DST is in
+effect or not.
 @end table
 
 @menu
@@ -54,7 +56,7 @@ not in effect, negative means no information about DST is available.
 * gmtime::      Convert time to UTC (GMT) traditional representation
 * localtime::   Convert time to local representation
 * mktime::      Convert time to arithmetic representation
-* strftime::    Flexible calendar time formatter
+* strftime::    Convert date and time to a user-formatted string
 * time::        Get current calendar time (as single number)
 * __tz_lock::   Lock time zone global variables
 * tzset::       Set timezone info
diff --git a/newlib/libc/time/wcsftime.c b/newlib/libc/time/wcsftime.c
new file mode 100644
index 000000000..323a6c2eb
--- /dev/null
+++ b/newlib/libc/time/wcsftime.c
@@ -0,0 +1,64 @@
+/*
+ * wcsftime.c
+ * Original Author:	Craig Howland, for Newlib
+ *
+ * Source actually uses strftime.c.
+ * Documentation for wcsftime() here, with minimal overlap.
+ */
+
+/*
+FUNCTION
+<<wcsftime>>--convert date and time to a formatted wide-character string
+
+INDEX
+	wcsftime
+
+ANSI_SYNOPSIS
+	#include <time.h>
+	#include <wchar.h>
+	size_t wcsftime(wchar_t *<[s]>, size_t <[maxsize]>,
+			const wchar_t *<[format]>, const struct tm *<[timp]>);
+
+DESCRIPTION
+<<strftime>> is equivalent to <<strftime>>, except that:
+ 
+The argument s points to the initial element of an array of wide characters
+into which the generated output is to be placed.
+ 
+The argument maxsize indicates the limiting number of wide characters.
+ 
+The argument format is a wide-character string and the conversion specifiers
+are replaced by corresponding sequences of wide characters.
+ 
+The return value indicates the number of wide characters.
+ 
+See <<strftime>> for the details of the format specifiers.
+
+RETURNS
+When the formatted time takes up no more than <[maxsize]> wide characters,
+the result is the length of the formatted wide string.  Otherwise, if the
+formatting operation was abandoned due to lack of room, the result is
+<<0>>, and the wide-character string starting at <[s]> corresponds to just those
+parts of <<*<[format]>>> that could be completely filled in within the
+<[maxsize]> limit.
+
+PORTABILITY
+C99 and POSIX require <<wcsftime>>, but do not specify the contents of
+<<*<[s]>>> when the formatted string would require more than
+<[maxsize]> characters.  Unrecognized specifiers and fields of
+<<timp>> that are out of range cause undefined results.  Since some
+formats expand to 0 bytes, it is wise to set <<*<[s]>>> to a nonzero
+value beforehand to distinguish between failure and an empty string.
+This implementation does not support <<s>> being NULL, nor overlapping
+<<s>> and <<format>>.
+
+SEEALSO
+<<strftime>>
+
+<<wcsftime>> requires no supporting OS subroutines.
+*/
+
+#include <time.h>
+#include <wchar.h>
+#define MAKE_WCSFTIME
+#include "../time/strftime.c"