Add and use incrementDateValue() and decrementDateValue()

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

@@ -1221,12 +1221,10 @@ public class DateTimeUtils {
             timeNanos -= correction;
             if (timeNanos < 0) {
                 timeNanos += NANOS_PER_DAY;
-                dateValue = DateTimeUtils
-                        .dateValueFromAbsoluteDay(absoluteDayFromDateValue(dateValue) - 1);
+                dateValue = decrementDateValue(dateValue);
             } else if (timeNanos >= NANOS_PER_DAY) {
                 timeNanos -= NANOS_PER_DAY;
-                dateValue = DateTimeUtils
-                        .dateValueFromAbsoluteDay(absoluteDayFromDateValue(dateValue) + 1);
+                dateValue = incrementDateValue(dateValue);
             }
         }
         return ValueTimestampTimeZone.fromDateValueAndNanos(dateValue, timeNanos, (short) offsetMins);
@@ -1320,6 +1318,63 @@ public class DateTimeUtils {
         return dateValue(y, m + 3, (int) d);
     }
 
+    /**
+     * Return the next date value.
+     *
+     * @param dateValue
+     *            the date value
+     * @return the next date value
+     */
+    public static long incrementDateValue(long dateValue) {
+        int year = yearFromDateValue(dateValue);
+        if (year == 1582) {
+            // Use slow way instead of rarely needed large custom code.
+            return dateValueFromAbsoluteDay(absoluteDayFromDateValue(dateValue) + 1);
+        }
+        int day = dayFromDateValue(dateValue);
+        if (day < 28) {
+            return dateValue + 1;
+        }
+        int month = monthFromDateValue(dateValue);
+        if (day < getDaysInMonth(year, month)) {
+            return dateValue + 1;
+        }
+        day = 1;
+        if (month < 12) {
+            month++;
+        } else {
+            month = 1;
+            year++;
+        }
+        return dateValue(year, month, day);
+    }
+
+    /**
+     * Return the previous date value.
+     *
+     * @param dateValue
+     *            the date value
+     * @return the previous date value
+     */
+    public static long decrementDateValue(long dateValue) {
+        int year = yearFromDateValue(dateValue);
+        if (year == 1582) {
+            // Use slow way instead of rarely needed large custom code.
+            return dateValueFromAbsoluteDay(absoluteDayFromDateValue(dateValue) - 1);
+        }
+        if (dayFromDateValue(dateValue) > 1) {
+            return dateValue - 1;
+        }
+        int month = monthFromDateValue(dateValue);
+        if (month > 1) {
+            month--;
+        } else {
+            month = 12;
+            year--;
+        }
+        return dateValue(year, month, getDaysInMonth(year, month));
+    }
+
     /**
      * Append a date to the string builder.
      *

h2/src/main/org/h2/value/ValueTimestamp.java

@@ -62,7 +62,7 @@ public class ValueTimestamp extends Value {
 
     private ValueTimestamp(long dateValue, long timeNanos) {
         this.dateValue = dateValue;
-        if (timeNanos < 0 || timeNanos >= 24L * 60 * 60 * 1000 * 1000 * 1000) {
+        if (timeNanos < 0 || timeNanos >= DateTimeUtils.NANOS_PER_DAY) {
             throw new IllegalArgumentException("timeNanos out of range " + timeNanos);
         }
         this.timeNanos = timeNanos;
@@ -229,7 +229,7 @@ public class ValueTimestamp extends Value {
         long dv = dateValue;
         if (n2 >= DateTimeUtils.NANOS_PER_DAY) {
             n2 -= DateTimeUtils.NANOS_PER_DAY;
-            dv = DateTimeUtils.dateValueFromAbsoluteDay(DateTimeUtils.absoluteDayFromDateValue(dateValue) + 1);
+            dv = DateTimeUtils.incrementDateValue(dv);
         }
         return fromDateValueAndNanos(dv, n2);
     }

h2/src/main/org/h2/value/ValueTimestampTimeZone.java

@@ -70,7 +70,7 @@ public class ValueTimestampTimeZone extends Value {
 
     private ValueTimestampTimeZone(long dateValue, long timeNanos,
             short timeZoneOffsetMins) {
-        if (timeNanos < 0 || timeNanos >= 24L * 60 * 60 * 1000 * 1000 * 1000) {
+        if (timeNanos < 0 || timeNanos >= DateTimeUtils.NANOS_PER_DAY) {
             throw new IllegalArgumentException(
                     "timeNanos out of range " + timeNanos);
         }
@@ -218,7 +218,7 @@ public class ValueTimestampTimeZone extends Value {
         long dv = dateValue;
         if (n2 >= DateTimeUtils.NANOS_PER_DAY) {
             n2 -= DateTimeUtils.NANOS_PER_DAY;
-            dv = DateTimeUtils.dateValueFromAbsoluteDay(DateTimeUtils.absoluteDayFromDateValue(dateValue) + 1);
+            dv = DateTimeUtils.incrementDateValue(dv);
         }
         return fromDateValueAndNanos(dv, n2, timeZoneOffsetMins);
     }
@@ -228,25 +228,25 @@ public class ValueTimestampTimeZone extends Value {
         ValueTimestampTimeZone t = (ValueTimestampTimeZone) o;
         // Maximum time zone offset is +/-18 hours so difference in days between local
         // and UTC cannot be more than one day
-        long daysA = DateTimeUtils.absoluteDayFromDateValue(dateValue);
+        long dateValueA = dateValue;
         long timeA = timeNanos - timeZoneOffsetMins * 60_000_000_000L;
         if (timeA < 0) {
             timeA += DateTimeUtils.NANOS_PER_DAY;
-            daysA--;
+            dateValueA = DateTimeUtils.decrementDateValue(dateValueA);
         } else if (timeA >= DateTimeUtils.NANOS_PER_DAY) {
             timeA -= DateTimeUtils.NANOS_PER_DAY;
-            daysA++;
+            dateValueA = DateTimeUtils.incrementDateValue(dateValueA);
         }
-        long daysB = DateTimeUtils.absoluteDayFromDateValue(t.dateValue);
+        long dateValueB = t.dateValue;
         long timeB = t.timeNanos - t.timeZoneOffsetMins * 60_000_000_000L;
         if (timeB < 0) {
             timeB += DateTimeUtils.NANOS_PER_DAY;
-            daysB--;
+            dateValueB = DateTimeUtils.decrementDateValue(dateValueB);
         } else if (timeB >= DateTimeUtils.NANOS_PER_DAY) {
             timeB -= DateTimeUtils.NANOS_PER_DAY;
-            daysB++;
+            dateValueB = DateTimeUtils.incrementDateValue(dateValueB);
         }
-        int cmp = Long.compare(daysA, daysB);
+        int cmp = Long.compare(dateValueA, dateValueB);
         if (cmp != 0) {
             return cmp;
         }

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

@@ -377,6 +377,9 @@ public class TestDate extends TestBase {
                     assertEquals(y, DateTimeUtils.yearFromDateValue(date));
                     assertEquals(m, DateTimeUtils.monthFromDateValue(date));
                     assertEquals(d, DateTimeUtils.dayFromDateValue(date));
+                    long nextDateValue = DateTimeUtils.dateValueFromAbsoluteDay(next);
+                    assertEquals(nextDateValue, DateTimeUtils.incrementDateValue(date));
+                    assertEquals(date, DateTimeUtils.decrementDateValue(nextDateValue));
                 }
             }
         }