By "time" I assume you're trying to change the time counts for a certain step, or maybe the count resolution in 10ms increments. You can't do this by writing directly to the drum as those positions will only accept a constant input.
What I sometimes like to do with drums is to make the events control relays, then I can write more complex logic outside the drum that turns on the control relay. This outside logic can include anything you can program in ladder. Timers, counters, one shots, knock yourself out. Then you can use a V-Memory register as the setpoint for one of these normal external timers, and write to that.