ui formula fields can use datetime fields. They are just expressed in milliseconds.

So to subtract an hour, you want

{{Datetime__c}} - (1000*60*60)

I had thought so too but tried that many times in past and doesn’t display. The calculation seemed to work off Date fields to subtract a day but not DateTime. Just tried it now and still get blank. The DateTime field is in the model.

This thread from a bit back seems to confirm. Actually even the dates may not work I might have been mistaken.

https://community.skuid.com/t/ui-only-formula-fields-add-1-month-to-date

What do you get if you change the displaytype of the formula field to Text?

Zip. Output blank so far for Text, Date, DateTime.

But after I saw JDs respons that said this isn’t supported I stopped playing with it esp since seems like would be straightforward if it did work. If I remove the calculation it does display as a DateTime.

That’s so strange. Well, you can do it with a javascript snippet.

Yeah, not super versed in those so try to avoid if can but don’t we now have to put those as static resources also? I’m only passively following the changes in Salesforce but thought that was one of the big things at least coming, even if I get away with it for today.