What are the start and end times of the five daily prayers (Salat)?

According to Fiqh Ahmadiyya (p. 37–39):

• Fajr—Starts when night finishes and light begins to spread on the eastern horizon. Ends at sunrise. Lasting a little less than 1½ hours.
• Zuhar—Starts when the sun begins to decline. Ends when the shadow of an object is equal to its height, and can extend until when the shadow of an object is twice its height. Lasting about 3 hours.
• ‘Asr—Starts when the shadow of an object is three times its height, and can extend as early as when the shadow of an object is twice its height. Ends just before the sun sets. Lasting about 2–2½ hours.
• Maghrib—Starts when the sun sets. Ends with the disappearing of redness on the western horizon, and can extend until the disappear- ing of whiteness on the western horizon. Lasting a little less than 1
½ hours.
• ‘Isha’—Starts after the disappearing of whiteness on the western horizon. If need be, the end of Maghrib time and start of ‘Isha’ time can overlap during the time of whiteness on the western horizon. Ends when half of the night has passed, and can extend until before night finishes and the time of Fajr begins.

Concerning the end time of ‘Isha’, Hadrat Khalifatul-Masih IV ^ra explained that there is no hard and fast line that could be drawn between tahajjud and ‘Isha’. Once ‘Isha’ time begins, it is better to say it no later than midnight. Hadrat Musleh Mau‘ud ^ra was of the opinion that under ordinary circumstances, midnight should be treated as the end time for ‘Isha’. However, if someone is on a journey or under compelling conditions, and he is not going to sleep anyways, then even if he misses midnight, ‘Isha’ will still be within time technically speaking (Question Answer Session, Aug 20, 1984).