Django date to javascript at the template

Question

What would be the easy way of achieving such below? selected_date comes from django context as a python date :

<script type="text/javascript">
    var selected_year = {{ selected_date|date:"Y" }}
    var selected_month = {{ selected_date|date:"m" }} - 1;
    var selected_day = {{ selected_date|date:"d"}}
    var selected_date = new Date(selected_year, selected_month, selected_day);
    alert(selected_date);
</script>

Answer 1

I've had a lot of success with the isoformat function in python:

var selected_date = new Date("{{ selected_date.isoformat }}")

Answer 2

The accepted answer may generate an incorrect date depending on locale.

In FF console:

>>> n = new Date('2011-01-01');
Date {Fri Dec 31 2010 16:00:00 GMT-0800 (PST)}

It's therefore preferable to pass Y,m,d integers to the Date constructor.

I use a template filter to generate the date constructor:

@register.filter(name='jsdate')
def jsdate(d):
    """formats a python date into a js Date() constructor.
    """
    try:
        return "new Date({0},{1},{2})".format(d.year, d.month - 1, d.day)
    except AttributeError:
        return 'undefined'