Some timestamps with timezone were not converted correctly.

h2/src/docsrc/html/changelog.html

@@ -19,7 +19,11 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>Sequences with cache size smaller than 0 did not work correctly.
+<ul><li>Some timestamps with timezone were not converted correctly.
+    For example, in the PST timezone, the timestamp 2011-10-26 08:00:00Z was converted to
+    2011-10-25 25:00:00 instead of 2011-10-26 01:00:00.
+    Depending on the database operation, this caused subsequent error.
+</li><li>Sequences with cache size smaller than 0 did not work correctly.
 </li><li>Issue 356: for Blob objects, InputStream.skip() returned 0, 
     causing EOFException in Blob.getBytes(.., ..).
 </li><li>Updateable result sets: if the value is not set when inserting a new row,

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

@@ -26,6 +26,9 @@ import org.h2.value.ValueTimestamp;
 
 /**
  * This utility class contains time conversion functions.
+ * <p>
+ * Date value: a bit field with bits for the year, month, and day.
+ * Absolute day: the day number (0 means 1970-01-01).
  */
 public class DateTimeUtils {
 
@@ -34,7 +37,7 @@ public class DateTimeUtils {
      */
     public static final long MILLIS_PER_DAY = 24 * 60 * 60 * 1000L;
 
-    private static final long NANOS_PER_DAY = MILLIS_PER_DAY * 1000000;
+    public static final long NANOS_PER_DAY = MILLIS_PER_DAY * 1000000;
 
     private static final int SHIFT_YEAR = 9;
     private static final int SHIFT_MONTH = 5;
@@ -325,10 +328,10 @@ public class DateTimeUtils {
     }
 
     /**
-     * Calculate the milliseconds for the given date and time in the specified
-     * timezone.
+     * Calculate the milliseconds since 1970-01-01 (UTC) for the given date and
+     * time (in the specified timezone).
      *
-     * @param tz the timezone
+     * @param tz the timezone of the parameters
      * @param year the absolute year (positive or negative)
      * @param month the month (1-12)
      * @param day the day (1-31)
@@ -336,7 +339,7 @@ public class DateTimeUtils {
      * @param minute the minutes (0-59)
      * @param second the number of seconds (0-59)
      * @param millis the number of milliseconds
-     * @return the number of milliseconds
+     * @return the number of milliseconds (UTC)
      */
     public static long getMillis(TimeZone tz, int year, int month, int day, int hour, int minute, int second, int millis) {
         try {

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

@@ -151,8 +151,10 @@ public class ValueTimestamp extends Value {
                 minute -= hour * 60;
                 long millis = DateTimeUtils.getMillis(tz, year, month, day, hour, minute, (int) second, (int) ms);
                 ms = DateTimeUtils.convertToLocal(new Date(millis), Calendar.getInstance(TimeZone.getTimeZone("UTC")));
-                dateValue = DateTimeUtils.dateValueFromDate(ms);
-                nanos += (ms - DateTimeUtils.absoluteDayFromDateValue(dateValue) * DateTimeUtils.MILLIS_PER_DAY) * 1000000;
+                long mpd = DateTimeUtils.MILLIS_PER_DAY;
+                long absoluteDay = (ms >= 0 ? ms : ms - mpd + 1) / mpd;
+                ms -= absoluteDay * mpd;
+                nanos += ms * 1000000;
             }
         }
         return ValueTimestamp.fromDateValueAndNanos(dateValue, nanos);

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

@@ -52,6 +52,7 @@ public class TestDate extends TestBase {
         testValueDate();
         testValueTime();
         testValueTimestamp();
+        testValueTimestampWithTimezone();
         testValidDate();
         testAbsoluteDay();
         testCalculateLocalMillis();
@@ -175,6 +176,21 @@ public class TestDate extends TestBase {
                 convertTo(Value.DATE).getString());
     }
 
+    private void testValueTimestampWithTimezone() {
+        for (int m = 1; m <= 12; m++) {
+            for (int d = 1; d <= 28; d++) {
+                for (int h = 0; h <= 23; h++) {
+                    String s = "2011-" + (m < 10 ? "0" : "") + m + "-" + (d < 10 ? "0" : "") + d + " " +
+                        (h < 10 ? "0" : "") + h + ":00:00";
+                    ValueTimestamp ts = ValueTimestamp.parse(s + "Z");
+                    String s2 = ts.getString();
+                    ValueTimestamp ts2 = ValueTimestamp.parse(s2);
+                    assertEquals(ts.getString(), ts2.getString());
+                }
+            }
+        }
+    }
+
     private void testValueTimestamp() {
         assertEquals("2001-02-03 04:05:06.0", ValueTimestamp.get(
                 Timestamp.valueOf("2001-02-03 04:05:06")).getString());