Need to improve date validation

[leopold@…]

when I input a invalid date, for example 0256-02-02, this date unexpectedly pass the validation of date field.
because the _datere = r'\d{4}-((?:0?[1-9])|(?:1[0-2]))-((?:0?[1-9])|(?:[12][0-9])|(?:3[0-1]))' " in validators.py don't forbid the invalid year number. this will lead to error message "year=256 is before 1900; the datetime strftime() methods require year >= 1900" . since django don't support small-number year, date validation should answer for this . I think
_datere = r'()((?:19[0-9]{2}|[2-9][0-9]{3}))-((?:0?[1-9])|(?:1[0-2]))-((?:0?[1-9])|(?:[12][0-9])|(?:3[0-1]))' to forbid invalid input or just change 'isValidaANSIDate' to replay the small-number year of error message.
At last, I wish django can replace hardcode of date and time format with variable in setting file, that will be more convient for changing output format of date field, thanks.

[Adrian Holovaty]

(In [2134]) Fixed #1070 -- Improved date validation to limit it to dates 1900 and up.