HTML/JS template filter to show localized dates/times - Django Template Filter

HTML/JS template filter to show localized dates/times

# ./utils/localdatetimefilters.py
from time import mktime
from google.appengine.ext import webapp

@register.filter("localdate")
def localdate(value, arg=None):
    from django.conf import settings
    from django.template import defaultfilters
    if not value:
        return ''
    if arg is None:
        arg = settings.DATE_FORMAT
    content = '''<script type="text/javascript">document.write(new Date(%d).toLocaleDateString().replace(/\s[A-Z]{3}\+[0-9]{4}/, '').replace(/\s\([\s\w]+\)/, ''));</script><noscript>%s</noscript>''' % (
        mktime(value.utctimetuple())*1000,
        defaultfilters.date(value, arg)
    )
    return content

@register.filter("localtime")
def localtime(value, arg=None):
    from django.conf import settings
    from django.template import defaultfilters
    if not value:
        return ''
    if arg is None:
        arg = settings.TIME_FORMAT
    content = '''<script type="text/javascript">document.write(new Date(%d).toLocaleTimeString().replace(/\s[A-Z]{3}\+[0-9]{4}/, '').replace(/\s\([\s\w]+\)/, ''));</script><noscript>%s</noscript>''' % (
        mktime(value.utctimetuple())*1000,
        defaultfilters.time(value, arg)
    )
    return content

@register.filter("localdatetime")
def localdatetime(value, arg1=None, arg2=None):
    from django.conf import settings
    from django.template import defaultfilters
    if not value:
        return ''
    if arg1 is None:
        arg1 = settings.DATE_FORMAT
    if arg2 is None:
        arg2 = settings.TIME_FORMAT
    content = '''<script type="text/javascript">document.write(new Date(%d).toLocaleString().replace(/\s[A-Z]{3}\+[0-9]{4}/, '').replace(/\s\([\s\w]+\)/, ''));</script><noscript>%s %s</noscript>''' % (
        mktime(value.utctimetuple())*1000,
        defaultfilters.date(value, arg1),
        defaultfilters.time(value, arg2)
    )
    return content

register = webapp.template.create_template_register()
register.filter(localdate)
register.filter(localtime)
register.filter(localdatetime)

# ./main.py (Request handler)
from google.appengine.ext import webapp
from google.appengine.ext.webapp import template

def main():
    webapp.template.register_template_library('utils.localdatetimefilters')