Now: http://xkcd.com/1335/

xkcd_now.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# See: http://xkcd.com/1335/
#
# Usage:
#   $ python xkcd_now.py
#   $ convert -delay 10 -loop 0 *.png animation.gif

from __future__ import print_function

import gevent.monkey
gevent.monkey.patch_socket()

from os.path import basename
from datetime import date, datetime, time, timedelta

import requests
import gevent


def time_iterator(from_time, to_time, delta=timedelta(minutes=0)):
    today = date.today()
    from_date = datetime.combine(today, from_time)
    to_date = datetime.combine(today, to_time)

    from_date = from_date or datetime.now()
    while to_date is None or from_date <= to_date:
        yield from_date
        from_date = from_date + delta
    return


def download_file(url, filename=None):
    filename = filename or basename(url)
    req = requests.get(url)
    if req.status_code != 200:
        print('[Error] %s: status code %s' % (url, req.status_code))
        return
    with open(filename, 'wb') as f:
        print('Downloading %s...' % filename)
        for chunk in req.iter_content():
            f.write(chunk)


def xkcd_nowurl(time_):
    return 'http://imgs.xkcd.com/comics/now/{0}.png'.format(time_.strftime('%Hh%Mm'))


def main():
    from_time = time(0, 0)
    to_time = time(23, 59)
    delta = timedelta(minutes=15)
    gevent.joinall([gevent.spawn(download_file, xkcd_nowurl(time_)) for time_ in time_iterator(from_time, to_time, delta)])

if __name__ == '__main__':
    main()