How to Fill Missing Fajr Times in a Mosque’s October 2026 Timetable

A blank cell in a mosque’s October 2026 prayer timetable is a small printing problem with a large practical effect. Fajr is the first prayer of the day, and if its time is missing from a printed schedule, the whole morning routine can become uncertain. This guide shows how to reconstruct a missing Fajr time from an astronomical twilight table and the standard solar depression angles used by North American prayer calculators.

Why Fajr times differ between sources

Fajr begins at the true dawn, the first horizontal spread of light along the horizon, and closes at sunrise. Arabic sources distinguish this true dawn, al-fajr al-ṣādiq, from the false dawn, a faint vertical light that appears earlier and fades back. A printed timetable is not observing the sky; it is the result of a calculation using a chosen solar depression angle. The two most common settings in North America are 15° for the Islamic Society of North America and 18° for the Muslim World League. Some other conventions use 19.5° for Egypt or 20° for Singapore, so a missing entry can only be filled correctly if you know which angle the mosque’s timetable was using.

Reading the U.S. Naval Observatory twilight table

The U.S. Naval Observatory publishes astronomical twilight times for locations and dates throughout 2026. Morning astronomical twilight is the instant when the sun is 18° below the eastern horizon before sunrise. If your mosque follows the 18° method, that twilight time is the Fajr time. If your mosque follows the ISNA or Fiqh Council of North America 15° method, the correct Fajr is slightly later, when the sun has risen from 18° to 15° below the horizon. Because the astronomical twilight table only gives the 18° moment, you cannot read a 15° Fajr directly from it; you need a calculator that can compute the 15° angle for the same date and location, or you need to confirm the mosque’s method first.

Interpolating from surrounding dates

Often the fastest reconstruction uses the two nearest published Fajr times around the gap. In New York, for example, the October 2026 timetable from SalahPortal lists Fajr at 06:03 on 26 October and 06:06 on 28 October. A missing entry for 27 October falls almost halfway between them, and in fact the published value is 06:04. If your mosque’s timetable has a gap, find the printed times on the dates either side and take the midpoint, then adjust it by the same number of minutes the surrounding days changed. This works well for October because the change from day to day is small, but it is an estimate, not a calculation.

Confirming with a calculation method you trust

Before you print a corrected timetable, compare your reconstructed time to a reliable prayer-time service that lets you set the method explicitly. IslamicFinder, for instance, displays the method under its prayer times and lists Fajr for Sun City Center, Florida, on 27 October 2026 as 06:32 AM using ISNA 15° and the Hanbali, Maliki, Shafi Asr view. Enter your own city, choose the matching method, and check the date; if the service’s Fajr is within a minute or two of your interpolation, the blank is safe to fill. If it differs by more than a few minutes, re-examine which depression angle the mosque uses.

When the missing entry is a word-finder problem

There is a small parallel with crossword solving. Once you know the surrounding prayer times and the calculation method, filling the blank is like completing a word from known letters and a known length. For Danish animal-name clues, DyrKrydsord is a dansk-language resource that matches animal names by letter count and known letters. The tool is not for prayer times, but the habit of using partial information to close a specific gap is the same.

A repeatable cross-check

To fill a missing Fajr time in your mosque’s October 2026 timetable, first determine whether the timetable uses 15° or 18°, then locate your city’s astronomical twilight time from the U.S. Naval Observatory table for the missing date. If the mosque uses 18°, that twilight time is your answer. If it uses 15°, interpolate from the surrounding dates or compute the 15° moment with a trustworthy calculator, and confirm against a service set to the same method. Print the corrected time with a note so the gap does not reappear in next year’s template.