Caught out by daylight saving :-(

[andrew cooke]

these are utilities i use that might help:

def parse_utc_date(day, formats=None):
    '''
    Return the epoch for a given UTC date.
    '''
    if day is None:
        return time()
    if formats is None:
        formats = ('%Y-%m-%d %H:%M:%S %Z', '%Y-%m-%d %Z', '%Y-%B-%d %Z')
    day = day.strip()
    if not day.endswith('UTC'):
        day += ' UTC'
    exception = None
    for format in formats:
        try:
            return timegm(strptime(day, format))
        except Exception, e:
            #LOG.debug(format_exc())
            exception = e
    if exception:
        raise ValueError(_('Could not parse %s: %s') % (day, exception))
    else:
        raise ValueError(_('Could not parse %s') % (day))

def format_utc_date(epoch, format='%Y-%m-%d %H:%M:%S UTC'):
    date_ = datetime.utcfromtimestamp(epoch)
    return date_.strftime(format)


andrew


CinnamonDonkey wrote:
> Hi All,
>
> I had the following bit of code which was working fine until we went
> into Daylight saving this weekend, now the result is an hour out.
>
>     timeString = "20090330 15:45:23"
>
>     timeFormat = '%Y-%m-%d %H:%M:%S'
>
>     modificationTime = datetime.datetime.utcfromtimestamp( time.mktime
> ( time.strptime( timeString, timeFormat ) ) )
>     minutesToAdvance = datetime.timedelta( minutes=5 )
>
>     modificationTime = modificationTime + minutesToAdvance
>
>     datetimeString = str ( modificationTime ).replace( ' ', 'T' )
>
>
> The expected result should be:
>
>     datetimeString = "20090330T15:50:23"
>
> But instead I get:
>
>     datetimeString = "20090330T14:50:23"
>
> I believe it is going wrong at either the mktime() or utcfromtimestamp
> () stage.
>
> What is the correct way to fix this compensating for daylight saving
> automatically?
>
> Regards,
> SHaun >8)
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>