Add DateTimeUtils.dateValueFromDenormalizedDate()

h2/src/main/org/h2/util/DateTimeUtils.java

@@ -1033,6 +1033,36 @@ public class DateTimeUtils {
         return (year << SHIFT_YEAR) | (month << SHIFT_MONTH) | day;
     }
 
+    /**
+     * Get the date value from a given denormalized date.
+     *
+     * @param year
+     *            the year
+     * @param month
+     *            the month, if out of range month and year will be normalized
+     * @param day
+     *            the day of the month, if out of range it will be saturated
+     * @return the date value
+     */
+    public static long dateValueFromDenormalizedDate(long year, long month, int day) {
+        long mm1 = month - 1;
+        long yd = mm1 / 12;
+        if (mm1 < 0 && yd * 12 != mm1) {
+            yd--;
+        }
+        int y = (int) (year + yd);
+        int m = (int) (month - yd * 12);
+        if (day < 1) {
+            day = 1;
+        } else {
+            int max = getDaysInMonth(y, m);
+            if (day > max) {
+                day = max;
+            }
+        }
+        return dateValue(y, m, day);
+    }
+
     /**
      * Convert a UTC datetime in millis to an encoded date in the default
      * timezone.

h2/src/test/org/h2/test/unit/TestDateTimeUtils.java

@@ -11,6 +11,8 @@ import java.util.GregorianCalendar;
 import org.h2.test.TestBase;
 import org.h2.util.DateTimeUtils;
 
+import static org.h2.util.DateTimeUtils.dateValue;
+
 /**
  * Unit tests for the DateTimeUtils class
  */
@@ -30,6 +32,7 @@ public class TestDateTimeUtils extends TestBase {
         testParseTimeNanosDB2Format();
         testDayOfWeek();
         testWeekOfYear();
+        testDateValueFromDenormalizedDate();
     }
 
     private void testParseTimeNanosDB2Format() {
@@ -53,7 +56,7 @@ public class TestDateTimeUtils extends TestBase {
             if (gc.get(Calendar.ERA) == GregorianCalendar.BC) {
                 year = 1 - year;
             }
-            long expectedDateValue = DateTimeUtils.dateValue(year, gc.get(Calendar.MONTH) + 1,
+            long expectedDateValue = dateValue(year, gc.get(Calendar.MONTH) + 1,
                     gc.get(Calendar.DAY_OF_MONTH));
             long dateValue = DateTimeUtils.dateValueFromAbsoluteDay(i);
             assertEquals(expectedDateValue, dateValue);
@@ -90,4 +93,15 @@ public class TestDateTimeUtils extends TestBase {
         }
     }
 
+    /**
+     * Test for {@link DateTimeUtils#dateValueFromDenormalizedDate(long, long, int)}.
+     */
+    private void testDateValueFromDenormalizedDate() {
+        assertEquals(dateValue(2017, 1, 1), DateTimeUtils.dateValueFromDenormalizedDate(2018, -11, 0));
+        assertEquals(dateValue(2001, 2, 28), DateTimeUtils.dateValueFromDenormalizedDate(2000, 14, 29));
+        assertEquals(dateValue(1999, 8, 1), DateTimeUtils.dateValueFromDenormalizedDate(2000, -4, -100));
+        assertEquals(dateValue(2100, 12, 31), DateTimeUtils.dateValueFromDenormalizedDate(2100, 12, 2000));
+        assertEquals(dateValue(-100, 2, 29), DateTimeUtils.dateValueFromDenormalizedDate(-100, 2, 30));
+    }
+
 }