Feature: Localizer Support in Date Utils

[lenehan2]

Do you want to request a feature or report a bug?

Feature

What's the current behavior?

Currently, much of the datetime math is handled using the browsers datetime via date-math.

When a timezone other than the user's browser is used, this causes a few unavoidable problems (at least unavoidable to the best of my knowledge). For instance in the Week view, the time will not start at 12:00 am.

Relevant issues:

#1478 (specifically this comment)
#118

What's the expected behavior?

When supplying a timezone/localizer, this timezone should be taken into consideration when making core date arithmetic.

[cutterbl]

@lenehan2 React-Big-Calendar now has full timezone support when using either the momentLocalizer or the new luxonLocalizer. The public documentation site is not yet up to date, but if you clone the repo you can run the 'examples' locally, giving you all of the details.