Imsak, which means refraining oneself, preventing, restraining and abstaining from, means as a religious term, “keeping away from eating, drinking, sexual intimacy and other things that break the fast starting from the white streak of dawn till the night sets in” (the Qur’an, al-Baqarah, 2:187)

The streak of dawn which starts the prohibitions of fasting is the time of imsak. By then, the deadline of the night prayer ends and the time of the morning prayer begins. This time is also when sahur ends and fasting begins. The time of sunset when prohibitions of fasting end is called the time of iftar. By this time, the time of the evening prayer begins. In places where day and night do not form fully, the time of imsak and iftar is determined with estimation.