Added Month.daysIn() and Year.isLeap()

tests/MonthTests.kt

@@ -0,0 +1,24 @@
+import io.fluidsonic.time.*
+import kotlin.test.*
+import kotlinx.datetime.*
+
+
+class MonthTests {
+
+	@Test
+	fun testDaysIn() {
+		assertEquals(expected = 31, actual = Month.JANUARY.daysIn(2000))
+		assertEquals(expected = 29, actual = Month.FEBRUARY.daysIn(2000))
+		assertEquals(expected = 28, actual = Month.FEBRUARY.daysIn(2001))
+		assertEquals(expected = 31, actual = Month.MARCH.daysIn(2000))
+		assertEquals(expected = 30, actual = Month.APRIL.daysIn(2000))
+		assertEquals(expected = 31, actual = Month.MAY.daysIn(2000))
+		assertEquals(expected = 30, actual = Month.JUNE.daysIn(2000))
+		assertEquals(expected = 31, actual = Month.JULY.daysIn(2000))
+		assertEquals(expected = 31, actual = Month.AUGUST.daysIn(2000))
+		assertEquals(expected = 30, actual = Month.SEPTEMBER.daysIn(2000))
+		assertEquals(expected = 31, actual = Month.OCTOBER.daysIn(2000))
+		assertEquals(expected = 30, actual = Month.NOVEMBER.daysIn(2000))
+		assertEquals(expected = 31, actual = Month.DECEMBER.daysIn(2000))
+	}
+}

tests/YearTests.kt

@@ -0,0 +1,20 @@
+import io.fluidsonic.time.*
+import kotlin.test.*
+
+
+class YearTests {
+
+	@Test
+	fun testIsLeap() {
+		val leapYears = listOf(
+			2000, 2004, 2008, 2012, 2016, 2020, 2024, 2028, 2032, 2036, 2040, 2044, 2048,
+			2052, 2056, 2060, 2064, 2068, 2072, 2076, 2080, 2084, 2088, 2092, 2096, 2104,
+		)
+
+		for (year in 1999 .. 2107)
+			if (leapYears.contains(year))
+				assertTrue(Year.isLeap(year), message = "Expected $year to be a leap year but it isn't.")
+			else
+				assertFalse(Year.isLeap(year), message = "Expected $year to not be a leap year but it is.")
+	}
+}