Salat times have been prescribed. … Indeed, performing prayers is a duty on the believers at the appointed times. (4:103)

The five obligatory prayers every 24 hours

  1. Fajr
    • 2 units
    • Its time starts when the true dawn (subh sadiq) appears and remains till just before sunrise.
  2. Zuhr
    • 4 units
    • Its time starts immediately after noon, i.e. when the sun has moved down from the center of the sky (zenith), and
    • the time remains till the shadow of every object becomes twice its size*
      • *according to Abu Hanifa.
      • However, his students, AY and Muhammad views are until shadow becomes equal to the size. Im. Tahawi considers this preferable.
  3. Asr
    • 4 units
    • End of zuhr until sunset
  4. Maghrib
    • 3 units
    • From sunset and remains till red twilight disappears*
      • Im. AY and M
      • AH later, until white twilight disappears 3 degrees, usually 12 minutes).
  5. Esha
    • 4 units
    • From disappearance of the twilight and remains till the true dawn appears.
  • Witr
    • 3 units ( Wajib)
    • Compulsory
    • Its start and end time are same as those of Îshä,
    • Must be offered after Îshä Saläh.

Reference material:

Desirable and undesirable salah times Salat