What is imsak? When does it begin?

Imsak, which literally means “to restrain oneself, to prevent, to abstain, to hold back,” is a religious term referring to abstaining from eating, drinking, sexual relations, and other things that invalidate the fast from the time of true dawn (fecr-i sâdık) until iftar. The opposite of imsak is iftar.

Among the public, “imsak” is used to refer to the time when the true dawn (fecr-i sâdık) occurs, marking the beginning of fasting. In this sense, imsak means the starting time for fasting.

The Qur’an explains when to start and end fasting as follows: “Eat and drink until you can discern the white thread of dawn from the black thread of night (until daybreak/fecr-i sâdık). Then complete the fast until nightfall (abstaining from eating, drinking, and sexual relations).” (al-Baqara, 2/187)

The “imsak” time shown in calendars indicates the starting time for fasting. Imsak is also the moment when the night ends, the time for the night prayer (isha) ends, and the time for the morning prayer (fajr) begins. During Ramadan, the adhan is also called at the beginning of imsak. Therefore, one must stop eating and drinking when the adhan begins. However, there is no harm in swallowing a morsel that is already in the mouth when the adhan starts.

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu