DateTime transforms ISO time string without timezone into UTC

[zmbc]

Short description of the problem:

When I use an <ion-datetime> and set the initial value to an ISO time string without a timezone (e.g. 2016-07-03T15:30), after changing the time the string now has a 'Z' at the end signifying UTC.

What behavior are you expecting?

It says in the Ionic docs:

Any of the ISO formats below can be used, and after a user selects a new value, Ionic will continue to use the same ISO format which datetime value was originally given as.
...
Date and Time | YYYY-MM-DDTHH:mm | 1994-12-15T13:47

I would expect, then, for my format (YYYY-MM-DDTHH:mm) to remain the same. Sorry if I have misunderstood this. If my issue is expected behavior, then I guess the docs should be updated.

Steps to reproduce:

1. Initialize an <ion-datetime> with an ISO string without a timezone specified.
2. Change the date using the picker.

Which Ionic Version?

2.x

Plunker that shows an example of your issue

http://plnkr.co/edit/w0aio9JY1osYKzOJaqtd?p=preview

[shyamal890]

Attaching a plunker example for reference: http://plnkr.co/edit/CJBcb6?p=preview

Also linking #8247

[mhartington]

So there's no good cross-platform way to handle this.
Each browser would do something different and it is very error prone.

A better way would be to use ngModel and a pipe

<ion-datetime 
  displayFormat="hh:mm A" 
  [ngModel]="firstDate | formatToLocal" 
  (ngModelChange)="firstDate=$event">
</ion-datetime>

This will let you pass the value to something like momentJS or Date-fns as a pipe then update the value on change as well

http://plnkr.co/edit/MHjUdC

[shyamal890]

@mhartington Have you even tested the solution? When you set the time value of firstDate look at it bounce to a different timezone. Please do reopen this issue. I would humbly suggest the output valueFormat only be in Timezone Offset => YYYY-MM-DDTHH:mm:ssTZD => 1994-12-15T13:47:20.789+5:00 format. May be that is the solution

[shyamal890]

Mike, suggests that Ionic wouldn't be handling this issue. Reference

Humbly tagging @adamdbradley @danbucholtz @mlynch to please have a relook at this issue.

[danbucholtz]

Hello,

Mike's solution for this is valid.

Thanks,
Dan