\D{format} yields the result of calling strftime(3) with the provided format.
With this change, all prompts will be able to use it.
This will enable us to easily generate timestamps when tracing script executionformat and the current time.
I would commit the two changes separately (and also a purely formatting change that I omitted here)When PS4 can use this, it will enable us to easily generate timestamps
when tracing script execution.