What is the ruling regarding someone who had intercourse with his wife multiple times during the daytime in Ramadan due to ignorance of the ruling?

Allah has forbidden eating, drinking, and sexual intercourse during the daytime in Ramadan. He has made it obligatory to offer expiation (kaffarah) for anyone who engages in sexual intercourse during the daytime in Ramadan, provided he is a responsible, healthy, resident individual. The expiation is the freeing of a slave. If one cannot find a slave, then it is fasting for two consecutive months. If one is unable to do that, then it is feeding sixty poor people. As for one who engages in sexual intercourse while ignorant of the obligation of expiation, the scholars have differed concerning him. The more cautious approach is that expiation is obligatory upon him due to his negligence in not inquiring. If intercourse is repeated on different days, the expiation is repeated according to the number of days. However, multiple instances of intercourse on a single day suffice with one expiation. It is advisable to act according to the more cautious approach when in doubt about the number of days, by taking the larger number.