javascript - Get UTC time given TZID and local time -

i trying parse .ics file in application. application has server side java layer , client side javascript part it. using ical4j library parse it.

problem dtstart of event not in utc format sometimes. , whenever not in utc .ics file has vtimezone component parsing , getting tzid property it.

java layer send json client. in above mentioned case dtstart, dtend , tzid being sent in json.

client has convert dtstart , dtend utc using tzid. tried moment.js since not find other api can this.

moment.tz("2014-02-06 05:30", "northamerica/eastern").format() 

with moment.js below error get,

typeerror: cannot call method 'rule' of undefined 

but below code works fine,

moment.tz("2014-02-06 17:30", "america/toronto").format() 

is not possible use tzid (i.e northamerica/eastern) .ics file? there other way or js library can give me utc timezones , considering observance?

you should aware icalendar specification rfc5545 states in tzid, that:

this document not define naming convention time zone identifiers. implementers may want use naming conventions defined in existing time zone specifications such public-domain tz database [tzdb]. specification of globally unique time zone identifiers not addressed document , left future study.

so while america/toronto listed in olsson database (see here), america/eastern not explains why js library cannot recognize it.

for robust design need either convert on server side utc or have actual js class capable parse ics vtimezone component.