-
The 0000 year is valid. The ISO standard for "Representation of dates and times" says: "Calendar years are numbered in ascending order according to the Gregorian calendar by values in the range [0000] to [9999]." Reverted fix for 21789: DATETIME with 0000-00-00 11:22:33 should be invalid, but is accepted as it's not a bug. Fix for 19370: DateTime datatype in MySQL has two bugs in it will be reverted during 4.1 -> 5.0 merging as it was pushed to the 5.0 tree.
fab56c1f