Improved PostgreSQL compatibility for timestamp literals with timezone.

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

@@ -278,7 +278,7 @@ public class DateTimeUtils {
                     if (timeZoneStart >= 0) {
                         String tzName = "GMT" + s.substring(timeZoneStart);
                         tz = TimeZone.getTimeZone(tzName);
-                        if (!tz.getID().equals(tzName)) {
+                        if (!tz.getID().startsWith(tzName)) {
                             throw Message.getSQLException(errorCode, new String[] { s, tz.getID() + " <>" + tzName });
                         }
                         s = s.substring(0, timeZoneStart).trim();

h2/src/test/org/h2/test/testSimple.in.txt

+select left(timestamp '2001-02-03 08:20:31+04', 4);
+> 2001;
+
 create table t1$2(id int);
 drop table t1$2;