value - ISO date string representing the current value.
I set, example, value="2018-03-21T17:19:40.815Z". With timezone on client, example, +07:00 i expect to get "2018-03-22" in calendar, but i get "2018-03-21"!
It happen because you modified value to "2018-03-21T12:00:00Z".
If you say that you want to get an ISO string - do not change the string! Or update you documentation - say that time in value does not matter for calendar.
In documentation:
I set, example, value="2018-03-21T17:19:40.815Z". With timezone on client, example, +07:00 i expect to get "2018-03-22" in calendar, but i get "2018-03-21"! It happen because you modified value to "2018-03-21T12:00:00Z". If you say that you want to get an ISO string - do not change the string! Or update you documentation - say that time in value does not matter for calendar.