A business requirement of a project is as follows:

The user needs to view historic dates based on his local time zone. For now, we store two dates in the database: UTC and the local time. The user needs to view the date in the (historic) time zone.

Example:

> 
> Database values: 2017-10-25T12:00:00 (UTC), 2017-10-25T09:00:00 (Date
>  of registration).
> 
> 
> 

From these values, we want the user to view the date in his time zone.

> 
> 2017-10-25T12:00:00 (UTC) to CEST (time zone offset +0200) =>
>  2017-10-25T14:00:00.
> 
> 
> 

However, when the user views the same date on a date where summer time does not apply, the user will see 2017-10-25T13:00:00 because CET is +0100.

I'm looking for a way in which it is possible to get the offset from UTC for the user's locale on the UTC date.

In short: get the UTC offset for a historic date in the user's local time zone.

***EDIT: libraries like Moment.js and Moment\_timezone.js are accepted!***