Ramadan does not begin on a fixed date in the Gregorian calendar because it follows the Islamic lunar calendar, which is about 10–11 days shorter than the solar year. The start of Ramadan depends on the sighting of the new crescent moon, marking the beginning of the ninth month in the Islamic calendar. As a result, the exact date can vary slightly from country to country, depending on local moon sightings or astronomical calculations used by religious authorities.
Typically, Islamic scholars and moon-sighting committees observe the sky shortly after sunset on the 29th day of the previous month, Sha’ban. If the crescent moon is visible, Ramadan begins the following day. If it is not seen, Sha’ban completes 30 days, and Ramadan starts the day after that. This process means that Muslims often wait for an official announcement from religious leaders or Islamic organizations before confirming the start date.
Because of these lunar calculations, Ramadan moves earlier each year in the Gregorian calendar. Over time, it rotates through different seasons, sometimes falling in summer and other times in winter. This shifting schedule allows Muslims around the world to experience fasting during various lengths of daylight hours, depending on where they live and the time of year.