Resetting millis() and micros() I want to know how much time has elapsed since a certain event, and I do not want to use any external timers. It seems logical to reset an internal timer whenever the event occurs (using an interrupt). Unfortunately, as far as I can tell, millis() and micros() cannot be manually reset. Obviously, I could save a time stamp whenever the event occurs; however, I want to avoid overflow problems (micros() will overflow every ~71 minutes, and millis() will overflow every ~50 days).

Is there a way to manually reset these built-in counters? If not, how can I manage the overflow?
millis() and micros() overflow periodically. However, this is not a
problem: as long as you compare durations instead of
timestamps you can
forget about the overflows.

The liked answer also gives the trick for resetting millis(). Can be
handy for testing purposes, but you do not need this to handle the
millis() rollover problem. Notice that there is no clean way to reset
micros(): it relies on a static variable, i.e. a variable private to
the file defining it.