Changed since Firebird 2.1:
CAST() as TYPE OF COLUMN
DATEADD: New unit WEEK. Sub-DAY units allowed with DATEs.
DATEDIFF: New unit WEEK. Sub-DAY units allowed with DATEs.
CHAR_TO_UUID()
LOG() behaviour improved
LOG10() behaviour improved
LPAD() now returns VARCHAR of exact end length
RPAD() now returns VARCHAR of exact end length
UUID_TO_CHAR()