September 15, 2014

Today we released updates to Guidance for OS X and iOS. In addition to some bug fixes, they have some improvements to the way they calculate prayer times.

  • We updated the Fajr time calculation for Umm Al-Qura to match the times found at
  • We added a new calculation method called “Gulf”. It is similar to Umm Al-Qura, but the fajr time calculation matches the times at This method is recommended for all gulf countries except Saudi Arabia (which uses the Umm Al-Qura method).
  • High latitude calculation now uses the seventh of the night method and is applied to locations above 55 degrees latitude instead of 48.5 degrees latitude.
  • The calculation method “Moonsighting Committee” has been added. This is the method developed by Khalid Shaukat of This method has been endorsed by the Fiqh Council of North America and is the basis for the “Unified Islamic Prayer Timetable for London”. As such, this method is the new default for the US and the UK. Please note, if you are calculating prayer times in London, the times may differ slightly from the “Unified Islamic Prayer Timetable for London” as Guidance always calculates times based on your precise current location, whereas the timetable has been calculated at a specific location inside of London.

For a more in depth analysis of how Guidance calculates prayer times please see our development blog at