If a person eats or drinks by mistake after the time for Sahur has ended (i.e., after the time of Imsak has begun), or before the time of Iftar, assuming that the time has not yet started or has already started, their fast for that day becomes invalid. However, since the fast was not broken intentionally, it is only required to make up that day (qada) after Ramadan; no expiation (kaffāra) is necessary.
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