You check the mosque timetable before work, then open a prayer app and see a different time. Which clock is wrong? Sometimes neither is malfunctioning. The two sources may use different locations, calculation rules, adjustments, or time-zone information. A few settings can move a displayed prayer time even when both systems calculate the sun's position correctly.
This is a practical explanation of the most common causes, not a religious ruling about which timetable you should follow. The best first step is to identify a trusted local mosque or authority, then make your device match that reference where possible. The aim is a dependable daily routine, not a contest between apps.
A prayer time is the result of several choices
A calculated timetable starts with a date and a location. It estimates the sun's position and applies definitions for particular prayer events. Some events depend on twilight, others on the sun's height or a shadow convention. Finally, the result is displayed in a civil time zone. Each stage can differ between two apps. A local mosque may also publish its own timetable or make a practical adjustment for congregation, which is a different concept from the astronomical start of a prayer window.
When you compare sources, compare the same date, city, and kind of time. A mosque's iqama time is the time a congregation begins; it is not necessarily the prayer's calculated start. Some calendars label both. Mixing them makes an app look late or early when it is simply showing a different event. If a timetable does not label a column clearly, ask the mosque before changing an app setting to match it.
| Possible cause | What changes | What to check |
|---|---|---|
| Different city or coordinates | Solar position used for the calculation | Selected city and device location |
| Fajr or Isha method | Twilight definition or method-specific rule | Calculation profile in both sources |
| Asr convention | Shadow threshold used for Asr | Asr or madhab setting |
| Time zone or daylight saving | Clock time shown for the same event | Mac time-zone settings and calendar date |
| Mosque timetable or adjustment | Published local reference or congregation time | Whether the column means adhan, start, or iqama |
Location and date come first
Sunrise and sunset are tied to place and date. An app set to a nearby city may be useful, but it is not identical to using your actual coordinates or your mosque's reference city. Check the city shown inside the app, especially after travel, a fresh installation, or a change to location permissions. A location label can be more useful than a vague ‘automatic’ indicator because it gives you something concrete to compare.
Also check the date on both schedules. A screenshot from yesterday or a monthly timetable read on the wrong row can mimic a calculation problem. Prayer times move from day to day, and their movement is not uniform through the year. If one schedule is printed, make sure it is for the current month and location. If you work across regions, do not assume that your Mac's home time zone is the one you are physically in.
Fajr and Isha may use different twilight rules
Fajr and Isha are associated with twilight rather than a simple clock offset from noon. Prayer-time software offers multiple calculation methods because organizations use different conventions, often expressed using a solar angle below the horizon. Some methods use other rules for Isha. Selecting another method can therefore change Fajr or Isha while leaving a prayer tied more directly to noon or sunset relatively closer. The name of a method matters more than an app's claim that its times are simply ‘accurate.’
Do not pick a method by changing settings until one app happens to match another on a single day. First find out which method or published timetable your local authority uses. Then compare multiple days and the specific prayer that differs. If your source does not map neatly to a named calculation profile, manual times or a local timetable can be more appropriate than forcing a profile to fit. At high latitudes, twilight behavior creates additional complications; seek local guidance rather than extrapolating from a timetable designed for another place.
Asr differences may come from the shadow convention
Asr calculations commonly expose a choice related to the length of an object's afternoon shadow. Different jurisprudential conventions use different thresholds. Many prayer-time libraries name the setting ‘Asr method’ or ‘madhab.’ If the other prayers look close but Asr is noticeably different, this setting is worth checking before assuming that the clock or location is broken.
This article cannot tell you which convention to follow. Your school, mosque, or trusted local authority is the right reference for that question. In practical terms, write down the convention you chose, because an app update or a new device can reset a default. If you share a timetable with family or colleagues, it helps to know whether your sources use the same Asr setting. The resulting comparison is then about two named methods, not a mysterious disagreement between phones.
The computer clock can make a correct calculation look wrong
A prayer time is eventually displayed as local clock time. If a Mac has the wrong time zone, even a correct calculation can appear at the wrong hour. Automatic time-zone selection is convenient, but it depends on device configuration and may need checking after travel. Apple documents where to set the Mac's date, time, and time zone. Verify those settings when every prayer appears displaced by a similar amount.
Daylight saving rules and government time changes can also alter the displayed clock. An old printed schedule or a device with outdated time-zone data may show a different local hour for the same solar event. The remedy is to confirm the current local time rules and update the system, not to add an arbitrary prayer-time offset. If only one prayer differs while the others agree, the clock is less likely to be the main cause; look at the prayer-specific method first.
Use a local timetable when it is your chosen reference
A mosque or religious ministry can publish times based on its own method and local review. In Morocco, the Ministry of Habous publishes prayer schedules for cities. A local reference can be particularly helpful where a generic global profile does not match the practice you follow. Keep a record of which city and source you selected so that another person can understand your setup later.
AlMiQaT supports automatic and manual prayer times. Its documentation also describes an official Morocco timetable option under the relevant Africa/Casablanca configuration. If the automatic times are not aligned with your trusted mosque, you can use manual times instead. Recheck them when the day changes; a manually entered schedule requires attention. The safest workflow is to compare the displayed times, confirm the reference, and test any scheduled device lock for a short duration before relying on it.
A five-minute comparison process
Put both schedules side by side for the same day. First compare city and time zone. Next ask whether the mosque column is a prayer start or an iqama time. Then find which prayers disagree: a broad shift suggests clock or location, while a difference concentrated in Fajr, Isha, or Asr points toward a method setting. Finally, compare the chosen calculation profile or local timetable with a trusted authority. Do not change five controls at once; change one and inspect the result.
Once the times match your chosen reference, save a note of the configuration and revisit it after travel, seasonal shifts, or a change in local guidance. The point is not to make every app on your devices identical. It is to know why your daily schedule says what it says and to avoid an alert or lock firing at a time you did not intend. A transparent choice is more useful than an unexplained claim of perfect accuracy.
Put it into practice
Explore the details and keep the routine that fits your day.