Allow Custom Date Picker to use a merchant-defined timezone

Request:

I’d like the Custom Date Picker to allow merchants to choose which timezone is used when determining available and blocked dates, instead of relying on the customer’s local browser timezone.

Why:

I deliver nationwide and close dates based on my operational schedule. Right now, customers in different U.S. timezones (especially Pacific and Mountain) can still select dates that are already closed on my end, which causes fulfillment issues.

How this helps:

Using a merchant-defined timezone (for example, my store’s timezone) would ensure date availability is consistent for all customers and prevent incorrect orders without forcing me to block extra days or lose sales.