Most Muslims pray five times a day, with their prayers being known as Fajr (before dawn), Dhuhr (afternoon), Asr (late afternoon), Maghrib (after sunset), and Isha (nighttime), always facing towards the Kaaba.

The five daily prayers are considered obligatory ( fard) by many and they are performed at times determined essentially by the position of the Sun in the sky. For example, the Maghrib prayer can be performed at any time after sunset and before the disappearance of the red twilight from the west. clarification needed] This prayer needs to be given in the middle of the work-day, and people normally make their prayers during their lunch break.In addition to the above measures, to calculate prayer times for a specific location we need its spherical coordinates. Dhuhr and asr time overlap, apart from the first 5 minutes of dhuhr, which is exclusively delegated for it. Time for dhuhr and asr prayers overlap, but the zuhr prayer must be offered before asr, except the time about 10 minutes before sunset, which is delegated exclusively to asr.

Per all major Jafari jurists, the end of dhuhr time is about 10 minutes before sunset, the time that belongs exclusively to asr prayer. displaystyle \lambda } and ϕ {\displaystyle \phi } are the longitude and the latitude of the considered point, respectively. Zuhr and Asr prayers must be offered before sunset, and the time for Asr starts after Zuhr has been prayed. Fajr begins at subh saadiq—true dawn or the beginning of twilight, when the morning light appears across the full width of the sky—and ends at sunrise. As a result, we have T F a j r = T D h u h r − T ( 18 ∘ ) {\displaystyle T_{\mathsf {Fajr}}=T_{\mathsf {Dhuhr}}-T(18There are varying opinions regarding the exact salah times, the schools of Islamic thought differing in minor details. Asr can be split into two sections; the preferred time is before the sun starts to turn orange, while the time of necessity is from when the sun turns orange until sunset.

The Isha'a or isha prayer starts at civil dusk when the darkness starts to spread across the sky, and lasts until nautical dusk when the western horizon gets completely dark and cannot be observed through naked eye. Sundial indicating prayer times, situated in the courtyard of the Great Mosque of Kairouan, Tunisia. The Asr prayer starts when the shadow of an object is the same length as the object itself (or, according to Hanafi school, twice its length) [ citation needed] plus the shadow length at zuhr, and lasts till sunset. This gives, in hours, the difference between Dhuhr time and when the sun is at altitude α {\displaystyle \alpha } . To calculate prayer times two astronomical measures are necessary, the declination of the sun and the difference between clock time and sundial clock.For the rest of Imams, "Asr starts when the shadow of an object becomes equal to its length (plus the length of its shadow at the start time of Zuhr). Because the start and end times for prayers are related to the solar diurnal motion, they vary throughout the year and depend on the local latitude and longitude when expressed in local time.