Daylight savings time does not seem to be handled correctly.

[tchari]

When creating a new moment at hour when daylight savings changes, Moment returns an invalid date error. Moment.js, on the other hand, returns the changed hour. For example:
$date = new Moment('2017-03-12 02:00:00', 'America/Edmonton);
return an invalid date. However, in moment.js
var now = moment('2017-03-12 02:00:00').format('MMM DD h:mm A');
returns "Mar 12 3:00 AM"

I believe the isValid() is unable to handle the daylight savings hour case.

[hriziya]

I wanted to use this library for my ongoing project but I am unsure on how this will handle the DST?

[tchari]

For my use case I was taking as input a date time string (e.g. 2018-04-05 15:00:00) and a time zone separately. I had to create a native DateTime and DateTimeZone object first and then create my Moment from the DateTime because the native class correctly handles DLS.

[hriziya]

I agree, but I am still not sure if creating the native DateTime and DateTimeZone would work..

here is the small sample I am worried about.
I am trying to convert America/Chicago time to UTC to store in database. but you can see that when I try to consider Timezone Name and Timezone Offset the output are different event with native DateTimeZone object. so I doubt Moment could handle this. This may not be the DST issue. but something related to it.

Any clue on this?

[tchari]

@hriziya
Super late on this reply; sorry

I don't think using the offset strategy vs. a named timezone is really comparable because there are a lot of different timezones that the same offset.

For example, lets say you were using a an offset of -7. In the summer months that offset corresponds to America/Whitehorse, America/Vancouver, America/Los_Angeles, among others. In the winter months, that offset corresponds to America/Whitehorse, America/Edmonton, America/Denver, etc.

If you're using a fixed offset would not expect DLS to ever really be handled appropriately because DLS is a jurisdiction-by-jurisdiction thing. I think if you use the named timezone, native PHP's DateTime and DateTimeZone classes should handle it properly.