When playing comps, can I pause and return at a later stage?

For the usual short competitions (i.e. 30-min, 45-min, 60-min, 75-min), you may pause/exit and return during that time period, but the timer will continue to run while you are away. You cannot return after that time period is over. So, by pausing/leaving you will lose playing time, and it will hurt your score.

For the long marathon competitions (i.e. 20-hr, 24-hr), you are free to exit and return throughout the whole time period.