Requiring coding in order to show anything in a timezone other than GMT is unnecessarily difficult and there should be an easy way to change the time zone on your profile so that all time-related fields will be reflected to each person in their time zone. For instance, if multiple contributors need to see a deadline they should see it in each of their own time zones. This seems to be a major design flaw since the main intention of this app is to make it easy to organize content and deadlines.
I think this is precisely the responsibility of web browsers. All data in Airtable is stored in UTC and the locale declared for each user’s browser renders the relative time.
This is exactly the behavior of Airtable as it already exists. If you turn off the GMT option, then everyone sees the deadline in their own time zones.
For a deep dive into time zones, please explore my sample base & training video: