Update one date field after date entry in another field
I'm entering a date a letter was received and want to just copy that date into another date field on the layout.
I've tried various techniques like OnObjectModify and OnObjectSave, but neither of these puts field1's contents into field2 after I TAB out of field1 in the script I wrote.
I also looked at the Manage Database, but those options seem constrained to just the field itself, not updating another field.
I'm sure there's a simple way to do this, but I don't see it.
How best to do this update?