If all you need is a calculated date to appear, see, for example, the topic Changing document dates during the course of a day in my Microsoft Word Date Calculation Tutorial, in the 'Sticky' thread at the top of this forum:
https://www.msofficeforums.com/word/...-tutorial.html
That example shows how to add a day after a certain (local) time, but could be adapted to subtract a day before a certain (local) time instead. If you need to change the date and time, see the Automatically Calculate A Past Or Future Time of Day and Add n Hours, Minutes & Seconds To a Starting Date & Time topics in the same tutorial.

However, any field calculation would affect the same document when opened/saved overseas, which seems rather different from what you actually need. The simple fact of the matter is that, if you're saving a document here, but it's being saved to a server in New Jersey, the save date & time can only be that of the New Jersey server. A possible workaround would be to save the document locally, then copy it to the New Jersey server.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]