I would be really useful for cases when you want to assign some limited time for solving some problem oftenly if there was hotkey to re-arm the timer. It's too tedious to do this through graphical menu each and every time. It also could be attached to the "Turns" feature, like, on the start of every turn timer is rearmed and starts counting down (could be an optional setting of the "Digital clock" object). Or it could be a separate setting of the "Turns" feature itself (i.e. ability to limit duration of the turn and optionally end it forcibly when time go out)