p-calendar doesn't display correct date when utc="true"

[johnhwright]

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Plunkr Case (Bug Reports)
http://embed.plnkr.co/heusWuPPLdRCOaG0u0AD/

Current behavior
When you select a date, the wrong value is shown in the field.

Expected behavior
The date selected will continue to be shown.

Minimal reproduction of the problem with instructions
See plunk

What is the motivation / use case for changing the behavior?
Visually the users need to see the date they chose, even if in UTC it's the day prior.

Please tell us about your environment:
N/A

• Angular version: 2.0.X
  4.2.6

• PrimeNG version: 2.0.X
  4.1.2

• Browser: all

• Language: all

• Node (for AoT issues): node --version = N/A

[mrbalcos]

I was not able to replicate this issue, but I have another issue, using your plunker, timezone does not seem to be set to UTC even if UTC was set to true

[ericsvendsen]

Looking at the source code for the calendar component, this is all the UTC property does:

if(this.utc)
    date = new Date(Date.UTC(dateMeta.year, dateMeta.month, dateMeta.day));
else
    date = new Date(dateMeta.year, dateMeta.month, dateMeta.day);

It creates a local Date object based on the UTC values for the year, month, and day you selected. So when you select a day (e.g. August 25), the component says "oh, you want the local date for 2017-08-25T00:00:00Z". I'm in EDT right now, so selecting the 25th renders Thu Aug 24 2017 20:00:00 GMT-0400 (EDT), and that's what is displayed in the control.

I was hoping that enabling UTC would allow the component to accept a UTC date input and then output the UTC date value in the control.

[ericsvendsen]

To be fair, I have since discovered that displaying a formatted date specific to a timezone won't be possible until Angular v5: angular/angular#9324

It looks like he got his PR done though and it's ready to be merged: angular/angular#18284. So hopefully PrimeNG will build this capability into their calendar component when the time comes.

[jonyadamit]

Hey @cagataycivici , you closed my issue (#4179) as duplicate of this. I hope you noticed I linked a PR for it.. (#4180).
The issue is shown more clearly in my plunker, which will allow testing the correctness of the fix.

[cagataycivici]

Merged PR from @jonyadamit #4180