On this page
What the control changes
AL-Naqawa’s Hijri date adjustment shifts the calculated Hijri result by the selected number of days. It is a calendar-conversion setting. Keep it separate from the minute adjustments used in a prayer timetable.
The calendar tools offer Umm al-Qura and Tabular Hijri calculations, with adjustments from minus two to plus two days. Choose the method first and note the adjustment alongside any result you save.
Try a fixed date rather than changing everything
Open the date converter with 29 October 2026 as the Gregorian date and Umm al-Qura as the method. Start at zero adjustment. Then compare minus one and plus one while keeping that same date and method selected.
In the Gregorian-to-Hijri direction, the Gregorian date you entered stays fixed while the calculated Hijri result shifts. Write down the input, method and adjustment before comparing your result with a community notice. A screenshot that omits those settings leaves an important part of the conversion unexplained.
What positive and negative mean
For that fixed Gregorian input, a positive adjustment moves the displayed Hijri result forward and a negative adjustment moves it backward. If the shift crosses a month boundary, the month or year label can change as well.
In the reverse direction, you are holding a Hijri input fixed and asking for its corresponding Gregorian date under the selected settings. Read the direction labels before comparing outputs; a reverse conversion is not the same input held still.
When a local date differs
The US Naval Observatory explains that an astronomical calendar gives approximate Islamic dates and that actual month starts can depend on crescent visibility and weather. A calculation result is useful for planning, but a manual day shift does not verify a moon sighting or create a local announcement.
If you follow a mosque or authority’s announced date, record that source and its location alongside the calculator settings. Keep a mismatch visible until you understand its cause instead of repeatedly changing the adjustment until an unexplained number looks familiar.
Save an explained result
Before sharing a converted date, include the conversion direction, input date, calculation method, adjustment and the local source you are following. Recheck the output after changing any one of these settings.
For an observance date, confirm with the relevant local authority. This guide explains the website’s conversion control; it does not determine when an observance begins for a community.
Sources and further reading
- US Naval Observatory: calculated Islamic dates and crescent visibility ↗Checked 29 October 2026
- AL-Naqawa: date converter and its current controls ↗Checked 29 October 2026
