Our team was unable to find any built-in functions for handling timezones/offsets and had to develop our own library that uses the built-in timezone database installed on our Redhat servers.

Check out this article: Time Zones and Offsets and ObjectScript, Oh My! | InterSystems Developer

Here's the related library: tz---ObjectScript-Time-Zone-Conversion-Library

Let me know if you have any questions/problems with this library.

Thank you!

I just posted Time Zones and Offsets and ObjectScript, Oh My! article on DC.  Thanks!

My tz - ObjectScript Time Zone Conversion Library project now supports Interoperability Rules/DTLs.  Thanks!