How to set actual shipment date or return date in JST to AR transaction date?

Summary:

When customer ships SO or receives RMA on March 13 at 8 am in JST(UTC+9), the AR transaction date is set to one day before the actual shipment date or return date, i.e. March 12, because March 13, 8 am JST is March 12 in UTC. How can customer pass the actual ship/return date in JST to AR?

Content (required):

I read following doc, but not sure how to change the code for JST.

• Customer would like to convert the date both for orders and returns.
• Customer would like to convert the date only for Japan orders, because other countries also use the same instance.