formatrfc2822datetime.py

def formatrfc2822datetime(value=None, usegmt=False):
    """Returns a date string as specified by RFC 2822 section 3.3., e.g.:
        
    Fri, 09 Nov 2001 01:08:47 +0900
        
    Optional value may be a datetime value. Timezone is respected.
    """
    # Note: we cannot use strftime() because that honors the locale and RFC
    # 2822 requires that day and month names be the English abbreviations.
    if value is None:
        value = datetime.datetime.today()
    if usegmt:
        # Convert to UTC/GMT
        value = value - value.utcoffset()
        zone = 'GMT'
    else:
        offset = value.utcoffset().seconds / 60
        # RFC 2822 3.3.: The form "+0000" SHOULD be used to indicate a
        # time zone at Universal Time.
        zone = '%s%02d%02d' % (offset < 0 and '-' or '+', offset // 60, offset % 60)
    return '%s, %02d %s %04d %02d:%02d:%02d %s' % (
        ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'][value.date().weekday()],
        value.day,
        ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
         'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][value.month - 1],
        value.year, value.hour, value.minute, value.second, zone)