I've read dozens of posts about Moment Timezone but I still have not found a clear answer to this:
I have an application with users all over the world and regardless of the browsers time zone, I ALWAYS want to display a date & time as EST or EDT, whichever is in effect at the time ("America/New_York"). Does moment-timezone.js need to be loaded only with data for America/New_York since that is the only time zone I want to display, or do I need data for all time zones where a user may be in order for moment-timezone to be able to convert from that time zone to America/New_York? I need to be able to convert FROM any time zone because as new users e onboard I cannot know in advance what timezone they (and their browser) will be.
Right now I am using moment-timezone-with-data.js but it's 190KB. At this point I think I would rather make a quick AJAX request and get the date & time from the server - it's easy to get the current date/time in the desired time zone in PHP.
I've read dozens of posts about Moment Timezone but I still have not found a clear answer to this:
I have an application with users all over the world and regardless of the browsers time zone, I ALWAYS want to display a date & time as EST or EDT, whichever is in effect at the time ("America/New_York"). Does moment-timezone.js need to be loaded only with data for America/New_York since that is the only time zone I want to display, or do I need data for all time zones where a user may be in order for moment-timezone to be able to convert from that time zone to America/New_York? I need to be able to convert FROM any time zone because as new users e onboard I cannot know in advance what timezone they (and their browser) will be.
Right now I am using moment-timezone-with-data.js but it's 190KB. At this point I think I would rather make a quick AJAX request and get the date & time from the server - it's easy to get the current date/time in the desired time zone in PHP.
Share Improve this question asked Oct 25, 2016 at 21:24 LouInALLouInAL 892 silver badges5 bronze badges2 Answers
Reset to default 3In short, you need only Am/NY if all you want to do is to convert some arbitrary moment to that timezone, because a call to moment() will produce an object that corresponds to 'UTCtime+ local offset'. You don't really care which tz it is out of as long as you know the time in UTC. What you get from Am/NY tz data is which offset is now applicable to time in UTC to get Am/NY time.
You need zone info for each zone you explicitly use in your application.
Adding America/New_York zone will be enough, if you just want to parse moment objects in the America/New_York timezone.
For example:
moment.tz.add("America/New_York|EST EDT EWT EPT|50 40 40 40|01010101010101010101010101010101010101010101010102301010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010|-261t0 1nX0 11B0 1nX0 11B0 1qL0 1a10 11z0 1qN0 WL0 1qN0 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1qN0 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1qN0 WL0 1qN0 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1qN0 WL0 1qN0 11z0 1o10 11z0 RB0 8x40 iv0 1o10 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1qN0 WL0 1qN0 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1o10 1fz0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1fz0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1fz0 1a10 1fz0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1fz0 1cN0 1cL0 1cN0 1cL0 s10 1Vz0 LB0 1BX0 1cN0 1fz0 1a10 1fz0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1fz0 1a10 1fz0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 14p0 1lb0 14p0 1nX0 11B0 1nX0 11B0 1nX0 14p0 1lb0 14p0 1lb0 14p0 1nX0 11B0 1nX0 11B0 1nX0 14p0 1lb0 14p0 1lb0 14p0 1lb0 14p0 1nX0 11B0 1nX0 11B0 1nX0 14p0 1lb0 14p0 1lb0 14p0 1nX0 11B0 1nX0 11B0 1nX0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0|21e6");
var s = moment.tz("America/New_York").format();
console.log(s); // Current time in New York
s = moment.tz("2016-03-01", "America/New_York").format();
console.log(s); // 2016-03-01T00:00:00-05:00<script src="https://cdnjs.cloudflare./ajax/libs/moment.js/2.15.2/moment.min.js"></script>
<script src="https://cdnjs.cloudflare./ajax/libs/moment-timezone/0.5.7/moment-timezone.min.js"></script>If you want to convert between zones you have to add both target and destination zone, for example:
moment.tz.add(["America/New_York|EST EDT EWT EPT|50 40 40 40|01010101010101010101010101010101010101010101010102301010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010|-261t0 1nX0 11B0 1nX0 11B0 1qL0 1a10 11z0 1qN0 WL0 1qN0 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1qN0 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1qN0 WL0 1qN0 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1qN0 WL0 1qN0 11z0 1o10 11z0 RB0 8x40 iv0 1o10 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1qN0 WL0 1qN0 11z0 1o10 11z0 1o10 11z0 1o10 11z0 1o10 1fz0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1fz0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1fz0 1a10 1fz0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1fz0 1cN0 1cL0 1cN0 1cL0 s10 1Vz0 LB0 1BX0 1cN0 1fz0 1a10 1fz0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 1cN0 1fz0 1a10 1fz0 1cN0 1cL0 1cN0 1cL0 1cN0 1cL0 14p0 1lb0 14p0 1nX0 11B0 1nX0 11B0 1nX0 14p0 1lb0 14p0 1lb0 14p0 1nX0 11B0 1nX0 11B0 1nX0 14p0 1lb0 14p0 1lb0 14p0 1lb0 14p0 1nX0 11B0 1nX0 11B0 1nX0 14p0 1lb0 14p0 1lb0 14p0 1nX0 11B0 1nX0 11B0 1nX0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Rd0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0 Op0 1zb0|21e6",
"Europe/Rome|CET CEST|-10 -20|0101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010|-2as10 M00 1cM0 1cM0 14o0 1o00 WM0 1qM0 17c0 1cM0 M3A0 5M20 WM0 1fA0 1cM0 16K0 1iO0 16m0 1de0 1lc0 14m0 1lc0 WO0 1qM0 GTW0 On0 1C10 Lz0 1C10 Lz0 1EN0 Lz0 1C10 Lz0 1zd0 Oo0 1C00 On0 1C10 Lz0 1zd0 On0 1C10 LA0 1C00 LA0 1zc0 Oo0 1C00 Oo0 1zc0 Oo0 1fC0 1a00 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1fA0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1fA0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1cM0 1fA0 1o00 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00|39e5"]);
var s = moment.tz("America/New_York").tz("Europe/Rome").format();
console.log(s); // Current time in Rome (converted from New York)
s = moment.tz('2016-03-01', "America/New_York").tz("Europe/Rome").format();
console.log(s); // 2016-03-01T06:00:00+01:00<script src="https://cdnjs.cloudflare./ajax/libs/moment.js/2.15.2/moment.min.js"></script>
<script src="https://cdnjs.cloudflare./ajax/libs/moment-timezone/0.5.7/moment-timezone.min.js"></script>Zone infos are in the packed format described here, while I took zone values from here.
Anyway plase note that moment-timezone provides a moment-timezone-with-data-2010-2020.min.js with all the zone data for years from 2010 to 2020 that is just 33 KB.