Reminder dialog: click snooze to be reminded again AT

[quant]

Concrete real life situation which just happened:

I have a certain task, to which I need to do some follow up call, reminder dialogue shows up, ... I make a call ... I'm told to call again at 16:45 when the person is back.

- call finished, my reminder dialogue still open. I need to be reminded at 16:45 to make the call again ... small problem, I need to calculate how to set the reminder (EDITED: I meant "snooze reminder").

It would be nice if I could set AT what time the reminder dialogue should show again, ie. I'd like to be able to set the "pending reminder" attribute in the reminder dialogue.

Thanks