JS@Fullcallendar - parseEvent in IE. Putting date as string

JS@Fullcallendar - parseEvent in IE. Putting date as string

I use great Fullcallendar script to present planned events. Everything
works fine except parsing events in Internet Explorer 9/10 (!). Here I
read that I should put date as string. After I put example date by hand
problem disappeared but I have multiple dates in variables. I don't know
how to string it to make it work.
events: [
{{foreach from=$band.band_events item=event name=events}}
{
title: 'Termin zajêty',
start: new
Date(Date.parse("{{$event.wedding_date}}")),
description: '{{$event.description}}',
id: {{$event.id}}
}
],
Yes, I have smarty here. I tried:
start: new Date(Date.parse("{{$event.wedding_date}}")).toString(),
start: '' + new Date(Date.parse("{{$event.wedding_date}}")) + '',
and some other without a success.