Parse one of the following date formats into a datetime object:

    .. sourcecode:: text

        Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 822, updated by RFC 1123
        Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
        Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format

    If parsing fails the return value is `None`.

    :param value: a string with a supported date format.
    :return: a :class:`datetime.datetime` object.

def parse_date(value):
    """Parse one of the following date formats into a datetime object:

    .. sourcecode:: text

        Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 822, updated by RFC 1123
        Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
        Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format

    If parsing fails the return value is `None`.

    :param value: a string with a supported date format.
    :return: a :class:`datetime.datetime` object.
    """
    if value:
        t = parsedate_tz(value.strip())
        if t is not None:
            try:
                year = t[0]
                # unfortunately that function does not tell us if two digit
                # years were part of the string, or if they were prefixed
                # with two zeroes.  So what we do is to assume that 69-99
                # refer to 1900, and everything below to 2000
                if year >= 0 and year <= 68:
                    year += 2000
                elif year >= 69 and year <= 99:
                    year += 1900
                return datetime(*((year,) + t[1:7])) - timedelta(seconds=t[-1] or 0)
            except (ValueError, OverflowError):
                return None