Until what time can the Isha prayer be performed?

The time for the Isha prayer begins after the time for the Maghrib prayer ends and continues until “imsak” (the time when dawn begins to break). (Tahâvî, Sharh Ma‘ani al-Athar, 1/159 [957-959]) The Isha prayer can be performed at any time within this period. However, some scholars have stated that, as with all obligatory prayers, it is more virtuous to perform the Isha prayer at the beginning of its time, based on the recommendation of the Prophet Muhammad (peace be upon him). On the other hand, some scholars, relying on other narrations, have said that it is more appropriate to perform the Isha prayer in the later part of the night. (Ibn Qudamah, al-Mughni, 1/278)

According to the Shafi‘i school, the time for the Isha prayer begins when the redness on the western horizon disappears and continues until dawn. However, in this school, the time for Isha is divided into four categories: “virtuous,” “optional,” “permissible,” and “excusable.” The virtuous time is at the beginning of the period. The optional time is the first third of the night. After this, until dawn, is the permissible time; it is allowed to perform Isha during this time, but it is disliked. The excusable time is the time of Maghrib when Isha is performed together with it (jam‘ taqdim) due to an excuse. (Nawawi, al-Majmu‘, 3/31)

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