Hi! With time zones, there is some timestamps that does not exist or are "ambiguous".
For example, timestamp '2017-10-15 00:00 America/Sao_Paulo' does not exist as it's in the gap where DST starts and had one hour advanced. And timestamp '2018-02-17 23:00 America/Sao_Paulo' are ambiguous as it may be before DST ended or just after it. In Firebird currently the first case is treated as the valid hour before it. The second case is treated as the "second hour", i.e., the hour after DST ended. I'm fine with the second case (I think an exception would be worse) but IMO the first case of invalid time is better treated with an exception. What do you think? Adriano Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
