A: Generally, players can postpone their games for any reason (when they need more time to make the moves due to holidays, illness, work, etc. or to simply take a break from chess).
However, there is a number of limitations in the game postponement rules that prevent its abuse. Specifically there is a "waiting period" after each postponement during which the player cannot postpone his/her games again (depends on the length of the previous postponement).
Also, if your opponent continues to make moves in any of his/her games during the postponement period, you will be able to cancel the postponement and
restore the original time control for the game. The corresponding link will appear on the game page (above the chess board) that would allow you to
cancel the postponement after your opponent makes 5 or more moves (in any of their games) during the postponement period.
Also, if you find your opponent's behavior annoying, you can add them to your
ignore list.
» Complete
game postponement rules