1 files changed, 21 insertions, 0 deletions
diff --git a/node_modules/es-abstract/2018/InLeapYear.js b/node_modules/es-abstract/2018/InLeapYear.js
new file mode 100644
index 000000000..38ba8fdc8
--- /dev/null
+++ b/node_modules/es-abstract/2018/InLeapYear.js
@@ -0,0 +1,21 @@
+'use strict';
+
+var GetIntrinsic = require('../GetIntrinsic');
+
+var $EvalError = GetIntrinsic('%EvalError%');
+
+var DaysInYear = require('./DaysInYear');
+var YearFromTime = require('./YearFromTime');
+
+// https://ecma-international.org/ecma-262/5.1/#sec-15.9.1.3
+
+module.exports = function InLeapYear(t) {
+	var days = DaysInYear(YearFromTime(t));
+	if (days === 365) {
+		return 0;
+	}
+	if (days === 366) {
+		return 1;
+	}
+	throw new $EvalError('Assertion failed: there are not 365 or 366 days in a year, got: ' + days);
+};