Ramadan Date Estimator

Enter a Gregorian year to estimate when Ramadan — the 9th month of the Islamic (Hijri) calendar and the month of fasting — begins. The tool finds the Hijri year whose Ramadan falls inside your chosen Gregorian year and shows the estimated start date with its weekday. It is useful for travel, work and school planning, but the true date is set by moon sighting.

How it works

The tool uses the tabular Islamic calendar (the arithmetical “Kuwaiti” civil algorithm), which assigns a fixed pattern of 29- and 30-day months and 11 leap years per 30-year cycle. It converts 1 Ramadan of the relevant Hijri year to a Julian Day Number (JDN), then converts that JDN to a Gregorian date using the standard Fliegel–Van Flandern inverse, which also yields the weekday.

To pick the right Hijri year, it approximates AH ≈ (Gregorian − 622) × 33 ÷ 32, then checks the year before, that year, and the year after so the returned 1 Ramadan always lands inside the Gregorian year you entered. Because this is arithmetic, the result is deterministic — but the announced start, fixed by physical moon sighting, can differ by 1–2 days and varies by country.

Example

Entering 2026 finds Hijri year 1447 AH and estimates 1 Ramadan at around 18 February 2026. The following year, 2027, it shifts roughly 11 days earlier to early February — illustrating how the lunar month drifts backward through the Gregorian seasons each year.

Always confirm with a local authority. This tool is privacy-first — everything runs in your browser and nothing is sent anywhere.