Fix Time API methods not existing on Android (closes bitfireAT/davx5#125)

- move all tests that use Time API or other desugared APIs to Android unit tests
- move resources for tests
- don't use LocalTime.ofInstant() because it requires API level 31 and is not desugared
- fix Locale test
- added warning to src/test/README.txt
- update Kotlin and slf4j dependency

41 files changed, 141 insertions, 99 deletions

diff --git a/build.gradle b/build.gradle
index 169b324..866151f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -4,7 +4,7 @@
 
 buildscript {
     ext.versions = [
-        kotlin: '1.7.0',
+        kotlin: '1.7.10',
         dokka: '1.5.0',
         ical4j: '3.2.5',
         // latest Apache Commons versions that don't require Java 8 (Android 7)
@@ -99,7 +99,7 @@ dependencies {
     // noinspection GradleDependency
     implementation "commons-io:commons-io:${versions.commonsIO}"
 
-    implementation 'org.slf4j:slf4j-jdk14:1.7.32'
+    implementation 'org.slf4j:slf4j-jdk14:1.7.36'
     implementation 'androidx.core:core-ktx:1.8.0'
 
     androidTestImplementation 'androidx.test:core:1.4.0'
diff --git a/src/test/java/at/bitfire/ical4android/AndroidTimeUtilsTest.kt b/src/androidTest/java/at/bitfire/ical4android/AndroidTimeUtilsTest.kt
index 2c68b95..9cb7653 100644
--- a/src/test/java/at/bitfire/ical4android/AndroidTimeUtilsTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/AndroidTimeUtilsTest.kt
@@ -7,8 +7,6 @@ package at.bitfire.ical4android
 import at.bitfire.ical4android.util.AndroidTimeUtils
 import net.fortuna.ical4j.data.CalendarBuilder
 import net.fortuna.ical4j.model.*
-import net.fortuna.ical4j.model.Date
-import net.fortuna.ical4j.model.TimeZone
 import net.fortuna.ical4j.model.component.VTimeZone
 import net.fortuna.ical4j.model.parameter.TzId
 import net.fortuna.ical4j.model.parameter.Value
@@ -19,11 +17,9 @@ import net.fortuna.ical4j.model.property.RDate
 import net.fortuna.ical4j.util.TimeZones
 import org.junit.Assert.*
 import org.junit.Test
-import java.io.InputStreamReader
 import java.io.StringReader
 import java.time.Duration
 import java.time.Period
-import java.util.*
 
 class AndroidTimeUtilsTest {
 
diff --git a/src/androidTest/java/at/bitfire/ical4android/BatchOperationTest.kt b/src/androidTest/java/at/bitfire/ical4android/BatchOperationTest.kt
index 27debf5..66310df 100644
--- a/src/androidTest/java/at/bitfire/ical4android/BatchOperationTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/BatchOperationTest.kt
@@ -20,8 +20,8 @@ import net.fortuna.ical4j.model.property.Attendee
 import net.fortuna.ical4j.model.property.DtEnd
 import net.fortuna.ical4j.model.property.DtStart
 import org.junit.*
-import org.junit.Assert.*
-
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
 import java.net.URI
 import java.util.*
 
diff --git a/src/test/java/at/bitfire/ical4android/DateUtilsTest.kt b/src/androidTest/java/at/bitfire/ical4android/DateUtilsTest.kt
index 395b8da..395b8da 100644
--- a/src/test/java/at/bitfire/ical4android/DateUtilsTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/DateUtilsTest.kt
diff --git a/src/test/java/at/bitfire/ical4android/EventTest.kt b/src/androidTest/java/at/bitfire/ical4android/EventTest.kt
index 6842974..f114bf3 100644
--- a/src/test/java/at/bitfire/ical4android/EventTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/EventTest.kt
@@ -1,6 +1,7 @@
 /***************************************************************************************************
  * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
  **************************************************************************************************/
+
 package at.bitfire.ical4android
 
 import net.fortuna.ical4j.model.Date
@@ -325,8 +326,8 @@ class EventTest {
     }
 
     private fun parseCalendar(fname: String, charset: Charset = Charsets.UTF_8): List<Event> =
-            javaClass.classLoader!!.getResourceAsStream("events/$fname").use { stream ->
-                return Event.eventsFromReader(InputStreamReader(stream, charset))
-            }
+        javaClass.classLoader!!.getResourceAsStream("events/$fname").use { stream ->
+            return Event.eventsFromReader(InputStreamReader(stream, charset))
+        }
 
 }
diff --git a/src/test/java/at/bitfire/ical4android/ICalPreprocessorTest.kt b/src/androidTest/java/at/bitfire/ical4android/ICalPreprocessorTest.kt
index e1d614b..e1d614b 100644
--- a/src/test/java/at/bitfire/ical4android/ICalPreprocessorTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/ICalPreprocessorTest.kt
diff --git a/src/test/java/at/bitfire/ical4android/ICalendarTest.kt b/src/androidTest/java/at/bitfire/ical4android/ICalendarTest.kt
index f2693be..ee0b944 100644
--- a/src/test/java/at/bitfire/ical4android/ICalendarTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/ICalendarTest.kt
@@ -53,15 +53,17 @@ class ICalendarTest {
 	@Test
 	fun testFromReader_calendarProperties() {
 		val calendar = ICalendar.fromReader(
-			StringReader("BEGIN:VCALENDAR\n" +
-				"VERSION:2.0\n" +
-				"METHOD:PUBLISH\n" +
-				"PRODID:something\n" +
-				"X-WR-CALNAME:Some Calendar\n" +
-				"COLOR:darkred\n" +
-				"X-APPLE-CALENDAR-COLOR:#123456\n" +
-				"END:VCALENDAR"
-		))
+			StringReader(
+				"BEGIN:VCALENDAR\n" +
+						"VERSION:2.0\n" +
+						"METHOD:PUBLISH\n" +
+						"PRODID:something\n" +
+						"X-WR-CALNAME:Some Calendar\n" +
+						"COLOR:darkred\n" +
+						"X-APPLE-CALENDAR-COLOR:#123456\n" +
+						"END:VCALENDAR"
+			)
+		)
 		assertEquals("Some Calendar", calendar.getProperty<Property>(ICalendar.CALENDAR_NAME).value)
 		assertEquals("darkred", calendar.getProperty<Property>(Color.PROPERTY_NAME).value)
 		assertEquals("#123456", calendar.getProperty<Property>(ICalendar.CALENDAR_COLOR).value)
@@ -141,28 +143,31 @@ class ICalendarTest {
 
     @Test
     fun testTimezoneDefToTzId_Valid() {
-		assertEquals("US-Eastern", ICalendar.timezoneDefToTzId("BEGIN:VCALENDAR\n" +
-				"PRODID:-//Example Corp.//CalDAV Client//EN\n" +
-				"VERSION:2.0\n" +
-				"BEGIN:VTIMEZONE\n" +
-				"TZID:US-Eastern\n" +
-				"LAST-MODIFIED:19870101T000000Z\n" +
-				"BEGIN:STANDARD\n" +
-				"DTSTART:19671029T020000\n" +
-				"RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10\n" +
-				"TZOFFSETFROM:-0400\n" +
-				"TZOFFSETTO:-0500\n" +
-				"TZNAME:Eastern Standard Time (US &amp; Canada)\n" +
-				"END:STANDARD\n" +
-				"BEGIN:DAYLIGHT\n" +
-				"DTSTART:19870405T020000\n" +
-				"RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4\n" +
-				"TZOFFSETFROM:-0500\n" +
-				"TZOFFSETTO:-0400\n" +
-				"TZNAME:Eastern Daylight Time (US &amp; Canada)\n" +
-				"END:DAYLIGHT\n" +
-				"END:VTIMEZONE\n" +
-				"END:VCALENDAR"))
+		assertEquals("US-Eastern", ICalendar.timezoneDefToTzId(
+			"BEGIN:VCALENDAR\n" +
+					"PRODID:-//Example Corp.//CalDAV Client//EN\n" +
+					"VERSION:2.0\n" +
+					"BEGIN:VTIMEZONE\n" +
+					"TZID:US-Eastern\n" +
+					"LAST-MODIFIED:19870101T000000Z\n" +
+					"BEGIN:STANDARD\n" +
+					"DTSTART:19671029T020000\n" +
+					"RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10\n" +
+					"TZOFFSETFROM:-0400\n" +
+					"TZOFFSETTO:-0500\n" +
+					"TZNAME:Eastern Standard Time (US &amp; Canada)\n" +
+					"END:STANDARD\n" +
+					"BEGIN:DAYLIGHT\n" +
+					"DTSTART:19870405T020000\n" +
+					"RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4\n" +
+					"TZOFFSETFROM:-0500\n" +
+					"TZOFFSETTO:-0400\n" +
+					"TZNAME:Eastern Daylight Time (US &amp; Canada)\n" +
+					"END:DAYLIGHT\n" +
+					"END:VTIMEZONE\n" +
+					"END:VCALENDAR"
+		)
+		)
 	}
 
 	@Test
@@ -171,10 +176,14 @@ class ICalendarTest {
 		assertNull(ICalendar.timezoneDefToTzId("/* invalid content */"))
 
         // time zone without TZID
-		assertNull(ICalendar.timezoneDefToTzId("BEGIN:VCALENDAR\n" +
-				"PRODID:-//Inverse inc./SOGo 2.2.10//EN\n" +
-				"VERSION:2.0\n" +
-				"END:VCALENDAR"))
+		assertNull(
+			ICalendar.timezoneDefToTzId(
+				"BEGIN:VCALENDAR\n" +
+						"PRODID:-//Inverse inc./SOGo 2.2.10//EN\n" +
+						"VERSION:2.0\n" +
+						"END:VCALENDAR"
+			)
+		)
     }
 
 
@@ -182,8 +191,9 @@ class ICalendarTest {
 	fun testVAlarmToMin_TriggerDuration_Negative() {
 		// TRIGGER;REL=START:-P1DT1H1M29S
 		val (ref, min) = ICalendar.vAlarmToMin(
-				VAlarm(Duration.parse("-P1DT1H1M29S")),
-				Event(), false)!!
+			VAlarm(Duration.parse("-P1DT1H1M29S")),
+			Event(), false
+		)!!
 		assertEquals(Related.START, ref)
 		assertEquals(60*24 + 60 + 1, min)
 	}
@@ -192,8 +202,9 @@ class ICalendarTest {
 	fun testVAlarmToMin_TriggerDuration_OnlySeconds() {
 		// TRIGGER;REL=START:-PT3600S
 		val (ref, min) = ICalendar.vAlarmToMin(
-				VAlarm(Duration.parse("-PT3600S")),
-				Event(), false)!!
+			VAlarm(Duration.parse("-PT3600S")),
+			Event(), false
+		)!!
 		assertEquals(Related.START, ref)
 		assertEquals(60, min)
 	}
@@ -202,8 +213,9 @@ class ICalendarTest {
 	fun testVAlarmToMin_TriggerDuration_Positive() {
 		// TRIGGER;REL=START:P1DT1H1M30S (alarm *after* start)
 		val (ref, min) = ICalendar.vAlarmToMin(
-				VAlarm(Duration.parse("P1DT1H1M30S")),
-				Event(), false)!!
+			VAlarm(Duration.parse("P1DT1H1M30S")),
+			Event(), false
+		)!!
 		assertEquals(Related.START, ref)
 		assertEquals(-(60*24 + 60 + 1), min)
 	}
@@ -270,8 +282,8 @@ class ICalendarTest {
 		val event = Event()
 		event.dtStart = DtStart(Date(currentTime))
 		val (ref, min) = ICalendar.vAlarmToMin(
-				VAlarm(Period.parse("-P1W1D")),
-				event, false
+			VAlarm(Period.parse("-P1W1D")),
+			event, false
 		)!!
 		assertEquals(Related.START, ref)
 		assertEquals(8*24*60, min)
diff --git a/src/test/java/at/bitfire/ical4android/Ical4jTest.kt b/src/androidTest/java/at/bitfire/ical4android/Ical4jTest.kt
index ad8d11b..7bd9292 100644
--- a/src/test/java/at/bitfire/ical4android/Ical4jTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/Ical4jTest.kt
@@ -21,14 +21,18 @@ class Ical4jTest {
     @Test
     fun testEmailParameter() {
         // https://github.com/ical4j/ical4j/issues/418
-        val e = Event.eventsFromReader(StringReader("BEGIN:VCALENDAR\n" +
-                "VERSION:2.0\n" +
-                "BEGIN:VEVENT\n" +
-                "SUMMARY:Test\n" +
-                "DTSTART;VALUE=DATE:20200702\n" +
-                "ATTENDEE;EMAIL=attendee1@example.com:sample:attendee1\n" +
-                "END:VEVENT\n" +
-                "END:VCALENDAR")).first()
+        val e = Event.eventsFromReader(
+            StringReader(
+                "BEGIN:VCALENDAR\n" +
+                        "VERSION:2.0\n" +
+                        "BEGIN:VEVENT\n" +
+                        "SUMMARY:Test\n" +
+                        "DTSTART;VALUE=DATE:20200702\n" +
+                        "ATTENDEE;EMAIL=attendee1@example.com:sample:attendee1\n" +
+                        "END:VEVENT\n" +
+                        "END:VCALENDAR"
+            )
+        ).first()
         assertEquals("attendee1@example.com", e.attendees.first.getParameter<Email>(Parameter.EMAIL).value)
     }
 
diff --git a/src/androidTest/java/at/bitfire/ical4android/LocaleNonWesternDigitsTest.kt b/src/androidTest/java/at/bitfire/ical4android/LocaleNonWesternDigitsTest.kt
index 81f0783..81f91c1 100644
--- a/src/androidTest/java/at/bitfire/ical4android/LocaleNonWesternDigitsTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/LocaleNonWesternDigitsTest.kt
@@ -5,8 +5,9 @@
 package at.bitfire.ical4android
 
 import net.fortuna.ical4j.model.property.TzOffsetFrom
+import org.junit.AfterClass
 import org.junit.Assert.assertEquals
-import org.junit.Before
+import org.junit.BeforeClass
 import org.junit.ComparisonFailure
 import org.junit.Test
 import java.time.ZoneOffset
@@ -15,13 +16,22 @@ import java.util.*
 class LocaleNonWesternDigitsTest {
 
     companion object {
-        val locale = Locale("fa", "ir", "u-un-arabext")
-    }
+        val origLocale = Locale.getDefault()
+        val testLocale = Locale("fa", "ir", "u-un-arabext")
+
+        @BeforeClass
+        @JvmStatic
+        fun setFaIrArabLocale() {
+            assertEquals("Persian (Iran) locale not available", "fa", testLocale.language)
+            Locale.setDefault(testLocale)
+        }
+
+        @AfterClass
+        @JvmStatic
+        fun resetLocale() {
+            Locale.setDefault(origLocale)
+        }
 
-    @Before
-    fun verifyLocale() {
-        assertEquals("Persian (Iran) locale not available", "fa", locale.language)
-        Locale.setDefault(locale)
     }
 
     @Test
diff --git a/src/test/java/at/bitfire/ical4android/TaskTest.kt b/src/androidTest/java/at/bitfire/ical4android/TaskTest.kt
index cbe0bcc..cbe0bcc 100644
--- a/src/test/java/at/bitfire/ical4android/TaskTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/TaskTest.kt
diff --git a/src/test/java/at/bitfire/ical4android/TimeApiExtensionsTest.kt b/src/androidTest/java/at/bitfire/ical4android/TimeApiExtensionsTest.kt
index 44a02a0..44a02a0 100644
--- a/src/test/java/at/bitfire/ical4android/TimeApiExtensionsTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/TimeApiExtensionsTest.kt
diff --git a/src/androidTest/java/at/bitfire/ical4android/impl/TestEvent.kt b/src/androidTest/java/at/bitfire/ical4android/impl/TestEvent.kt
index f9c9571..11270a1 100644
--- a/src/androidTest/java/at/bitfire/ical4android/impl/TestEvent.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/impl/TestEvent.kt
@@ -5,7 +5,6 @@
 package at.bitfire.ical4android.impl
 
 import android.content.ContentValues
-import android.provider.CalendarContract
 import android.provider.CalendarContract.Events
 import at.bitfire.ical4android.*
 import java.util.*
diff --git a/src/androidTest/java/at/bitfire/ical4android/impl/TestJtxIcalObject.kt b/src/androidTest/java/at/bitfire/ical4android/impl/TestJtxIcalObject.kt
index 57615fb..a1397e9 100644
--- a/src/androidTest/java/at/bitfire/ical4android/impl/TestJtxIcalObject.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/impl/TestJtxIcalObject.kt
@@ -5,7 +5,9 @@
 package at.bitfire.ical4android.impl
 
 import android.content.ContentValues
-import at.bitfire.ical4android.*
+import at.bitfire.ical4android.JtxCollection
+import at.bitfire.ical4android.JtxICalObject
+import at.bitfire.ical4android.JtxICalObjectFactory
 
 class TestJtxIcalObject(testCollection: JtxCollection<JtxICalObject>): JtxICalObject(testCollection) {
 
diff --git a/src/test/java/at/bitfire/ical4android/validation/EventValidatorTest.kt b/src/androidTest/java/at/bitfire/ical4android/validation/EventValidatorTest.kt
index c64d0d7..2af3fe8 100644
--- a/src/test/java/at/bitfire/ical4android/validation/EventValidatorTest.kt
+++ b/src/androidTest/java/at/bitfire/ical4android/validation/EventValidatorTest.kt
@@ -16,34 +16,34 @@ import net.fortuna.ical4j.model.property.RRule
 import org.junit.Assert.*
 import org.junit.Test
 import java.io.StringReader
-import java.util.*
 
 class EventValidatorTest {
 
-    val tzReg = TimeZoneRegistryFactory.getInstance().createRegistry()
+    companion object {
+        val tzReg = TimeZoneRegistryFactory.getInstance().createRegistry()
+    }
 
 
     // DTSTART and DTEND
 
-    @Test
-    fun testEnsureCorrectStartAndEndTime_noDtStart() {
-        assertThrows(InvalidCalendarException::class.java) {
-            val event = Event().apply {
-                dtEnd = DtEnd(DateTime("20000105T000000"))  // DATETIME
-                // no dtStart
-            }
-            EventValidator.correctStartAndEndTime(event)
+    @Test(expected = InvalidCalendarException::class)
+    fun testEnsureCorrectStartAndEndTime_noDtStart_DateTime() {
+        val event = Event().apply {
+            dtEnd = DtEnd(DateTime("20000105T000000"))  // DATETIME
+            // no dtStart
         }
+        EventValidator.correctStartAndEndTime(event)
+    }
 
-        assertThrows(InvalidCalendarException::class.java) {
-            Event.eventsFromReader(StringReader(
-                "BEGIN:VCALENDAR\n" +
-                "BEGIN:VEVENT\n" +
-                "UID:51d8529a-5844-4609-918b-2891b855e0e8\n" +
-                "DTEND;VALUE=DATE:20211116\n" +                   // DATE
-                "END:VEVENT\n" +
-                "END:VCALENDAR")).first()
-        }
+    @Test(expected = InvalidCalendarException::class)
+    fun testEnsureCorrectStartAndEndTime_noDtStart_Date() {
+        Event.eventsFromReader(StringReader(
+            "BEGIN:VCALENDAR\n" +
+            "BEGIN:VEVENT\n" +
+            "UID:51d8529a-5844-4609-918b-2891b855e0e8\n" +
+            "DTEND;VALUE=DATE:20211116\n" +                   // DATE
+            "END:VEVENT\n" +
+            "END:VCALENDAR")).first()
     }
 
     @Test
diff --git a/src/test/resources/events/all-day-0sec.ics b/src/androidTest/resources/events/all-day-0sec.ics
index 07679f2..07679f2 100644
--- a/src/test/resources/events/all-day-0sec.ics
+++ b/src/androidTest/resources/events/all-day-0sec.ics
diff --git a/src/test/resources/events/all-day-10days.ics b/src/androidTest/resources/events/all-day-10days.ics
index 52e6dbd..52e6dbd 100644
--- a/src/test/resources/events/all-day-10days.ics
+++ b/src/androidTest/resources/events/all-day-10days.ics
diff --git a/src/test/resources/events/all-day-1day.ics b/src/androidTest/resources/events/all-day-1day.ics
index 506d295..506d295 100644
--- a/src/test/resources/events/all-day-1day.ics
+++ b/src/androidTest/resources/events/all-day-1day.ics
diff --git a/src/test/resources/events/dst-only-vtimezone.ics b/src/androidTest/resources/events/dst-only-vtimezone.ics
index e49d74d..e49d74d 100644
--- a/src/test/resources/events/dst-only-vtimezone.ics
+++ b/src/androidTest/resources/events/dst-only-vtimezone.ics
diff --git a/src/test/resources/events/event-on-that-day.ics b/src/androidTest/resources/events/event-on-that-day.ics
index 0ccbd4f..0ccbd4f 100644
--- a/src/test/resources/events/event-on-that-day.ics
+++ b/src/androidTest/resources/events/event-on-that-day.ics
diff --git a/src/test/resources/events/latin1.ics b/src/androidTest/resources/events/latin1.ics
index 20d97d0..20d97d0 100644
--- a/src/test/resources/events/latin1.ics
+++ b/src/androidTest/resources/events/latin1.ics
diff --git a/src/test/resources/events/multiple.ics b/src/androidTest/resources/events/multiple.ics
index 6e300ab..6e300ab 100644
--- a/src/test/resources/events/multiple.ics
+++ b/src/androidTest/resources/events/multiple.ics
diff --git a/src/test/resources/events/one-event-with-exception-one-without.ics b/src/androidTest/resources/events/one-event-with-exception-one-without.ics
index 182711b..182711b 100644
--- a/src/test/resources/events/one-event-with-exception-one-without.ics
+++ b/src/androidTest/resources/events/one-event-with-exception-one-without.ics
diff --git a/src/test/resources/events/one-event-with-multiple-exceptions-one-without.ics b/src/androidTest/resources/events/one-event-with-multiple-exceptions-one-without.ics
index bff4528..bff4528 100644
--- a/src/test/resources/events/one-event-with-multiple-exceptions-one-without.ics
+++ b/src/androidTest/resources/events/one-event-with-multiple-exceptions-one-without.ics
diff --git a/src/test/resources/events/outlook1.ics b/src/androidTest/resources/events/outlook1.ics
index 000afaa..000afaa 100644
--- a/src/test/resources/events/outlook1.ics
+++ b/src/androidTest/resources/events/outlook1.ics
diff --git a/src/test/resources/events/recurring-only-exception.ics b/src/androidTest/resources/events/recurring-only-exception.ics
index 26012e1..26012e1 100644
--- a/src/test/resources/events/recurring-only-exception.ics
+++ b/src/androidTest/resources/events/recurring-only-exception.ics
diff --git a/src/test/resources/events/recurring-with-exception1.ics b/src/androidTest/resources/events/recurring-with-exception1.ics
index 0382497..0382497 100644
--- a/src/test/resources/events/recurring-with-exception1.ics
+++ b/src/androidTest/resources/events/recurring-with-exception1.ics
diff --git a/src/test/resources/events/two-events-without-exceptions.ics b/src/androidTest/resources/events/two-events-without-exceptions.ics
index be6290f..be6290f 100644
--- a/src/test/resources/events/two-events-without-exceptions.ics
+++ b/src/androidTest/resources/events/two-events-without-exceptions.ics
diff --git a/src/test/resources/events/two-line-description-without-crlf.ics b/src/androidTest/resources/events/two-line-description-without-crlf.ics
index 03c8b62..03c8b62 100644
--- a/src/test/resources/events/two-line-description-without-crlf.ics
+++ b/src/androidTest/resources/events/two-line-description-without-crlf.ics
diff --git a/src/test/resources/events/utf8.ics b/src/androidTest/resources/events/utf8.ics
index 87171a9..87171a9 100644
--- a/src/test/resources/events/utf8.ics
+++ b/src/androidTest/resources/events/utf8.ics
diff --git a/src/test/resources/events/vienna-evolution.ics b/src/androidTest/resources/events/vienna-evolution.ics
index 5f11911..5f11911 100644
--- a/src/test/resources/events/vienna-evolution.ics
+++ b/src/androidTest/resources/events/vienna-evolution.ics
diff --git a/src/test/resources/tasks/empty-priority.ics b/src/androidTest/resources/tasks/empty-priority.ics
index 69ad1ae..69ad1ae 100644
--- a/src/test/resources/tasks/empty-priority.ics
+++ b/src/androidTest/resources/tasks/empty-priority.ics
diff --git a/src/test/resources/tasks/latin1.ics b/src/androidTest/resources/tasks/latin1.ics
index b3502de..b3502de 100644
--- a/src/test/resources/tasks/latin1.ics
+++ b/src/androidTest/resources/tasks/latin1.ics
diff --git a/src/test/resources/tasks/most-fields1.ics b/src/androidTest/resources/tasks/most-fields1.ics
index ff4dbb0..ff4dbb0 100644
--- a/src/test/resources/tasks/most-fields1.ics
+++ b/src/androidTest/resources/tasks/most-fields1.ics
diff --git a/src/test/resources/tasks/most-fields2.ics b/src/androidTest/resources/tasks/most-fields2.ics
index f6c7215..f6c7215 100644
--- a/src/test/resources/tasks/most-fields2.ics
+++ b/src/androidTest/resources/tasks/most-fields2.ics
diff --git a/src/test/resources/tasks/rfc5545-sample1.ics b/src/androidTest/resources/tasks/rfc5545-sample1.ics
index 18d53df..18d53df 100644
--- a/src/test/resources/tasks/rfc5545-sample1.ics
+++ b/src/androidTest/resources/tasks/rfc5545-sample1.ics
diff --git a/src/test/resources/tasks/utf8.ics b/src/androidTest/resources/tasks/utf8.ics
index 67aaa1e..67aaa1e 100644
--- a/src/test/resources/tasks/utf8.ics
+++ b/src/androidTest/resources/tasks/utf8.ics
diff --git a/src/test/resources/tz/Karachi.ics b/src/androidTest/resources/tz/Karachi.ics
index 1515d2b..1515d2b 100644
--- a/src/test/resources/tz/Karachi.ics
+++ b/src/androidTest/resources/tz/Karachi.ics
diff --git a/src/test/resources/tz/Mogadishu.ics b/src/androidTest/resources/tz/Mogadishu.ics
index b5e4fd3..b5e4fd3 100644
--- a/src/test/resources/tz/Mogadishu.ics
+++ b/src/androidTest/resources/tz/Mogadishu.ics
diff --git a/src/test/resources/tz/Vienna.ics b/src/androidTest/resources/tz/Vienna.ics
index 5b0f65f..5b0f65f 100644
--- a/src/test/resources/tz/Vienna.ics
+++ b/src/androidTest/resources/tz/Vienna.ics
diff --git a/src/main/java/at/bitfire/ical4android/validation/EventValidator.kt b/src/main/java/at/bitfire/ical4android/validation/EventValidator.kt
index ac0e108..d8ee48c 100644
--- a/src/main/java/at/bitfire/ical4android/validation/EventValidator.kt
+++ b/src/main/java/at/bitfire/ical4android/validation/EventValidator.kt
@@ -12,11 +12,13 @@ import at.bitfire.ical4android.util.TimeApiExtensions.toIcal4jDate
 import at.bitfire.ical4android.util.TimeApiExtensions.toIcal4jDateTime
 import at.bitfire.ical4android.util.TimeApiExtensions.toLocalDate
 import at.bitfire.ical4android.util.TimeApiExtensions.toZoneIdCompat
-import net.fortuna.ical4j.model.Date
 import net.fortuna.ical4j.model.DateTime
 import net.fortuna.ical4j.model.property.DtStart
 import net.fortuna.ical4j.model.property.RRule
-import java.time.*
+import net.fortuna.ical4j.util.TimeZones
+import java.time.LocalTime
+import java.time.ZonedDateTime
+import java.util.*
 
 /**
  * Sometimes CalendarStorage or servers respond with invalid event definitions. Here we try to
@@ -63,17 +65,27 @@ class EventValidator(val e: Event) {
                     rRule.recur.until?.let { until ->
                         if (until !is DateTime) {
                             Ical4Android.log.warning("DTSTART has DATETIME, but UNTIL has DATE; copying time from DTSTART to UNTIL")
-                            val timeZone = if (dtStart.timeZone != null)
-                                dtStart.timeZone.toZoneIdCompat()
+                            val dtStartTimeZone = if (dtStart.timeZone != null)
+                                dtStart.timeZone
                             else if (dtStart.isUtc)
-                                ZoneOffset.UTC
+                                TimeZones.getUtcTimeZone()
                             else /* floating time */
-                                ZoneId.systemDefault()
+                                TimeZone.getDefault()
+
+                            val dtStartCal = Calendar.getInstance(dtStartTimeZone).apply {
+                                time = dtStart.date
+                            }
+                            val dtStartTime = LocalTime.of(
+                                dtStartCal.get(Calendar.HOUR_OF_DAY),
+                                dtStartCal.get(Calendar.MINUTE),
+                                dtStartCal.get(Calendar.SECOND)
+                            )
+
                             rRule.recur.until =
                                 ZonedDateTime.of(
-                                    until.toLocalDate(),                                        // date from until
-                                    LocalTime.ofInstant(dtStart.date.toInstant(), timeZone),    // time from dtStart
-                                    timeZone
+                                    until.toLocalDate(),    // date from until
+                                    dtStartTime,       // time from dtStart
+                                    dtStartTimeZone.toZoneIdCompat()
                                 ).toIcal4jDateTime()
                         }
                     }
diff --git a/src/test/README.txt b/src/test/README.txt
new file mode 100644
index 0000000..60a244a
--- /dev/null
+++ b/src/test/README.txt
@@ -0,0 +1,6 @@
+
+ATTENTION!
+
+Do not use JVM unit tests for methods the use the Time API or other APIs that behave
+differently in normal JVMs and the Android JVM. Especially do not write JVM unit tests
+that use APIs that are desugared in Android. Use Android unit tests (androidTest) instead.