What must we do if the state erred in determining the beginning and end of Ramadan, and it was proven that we missed a day of it?

If it is established through legitimate (Shar'i) means that Muslims erred in determining the beginning or end of Ramadan (definition), they must rectify the mistake and make up the day they broke their fast. This error can be established in several ways, including completing Sha'ban as thirty days and then a trustworthy person testifying to having sighted the crescent moon on the night of the thirtieth, or fasting Ramadan for twenty-eight days and then sighting the crescent moon of Shawwal. Ibn Baz affirmed that a month does not fall short of twenty-nine days, and that this occurred during the time of Ali, may Allah be pleased with him. This also happened in the Two Holy Mosques in the year 1404 AH, and the Permanent Committee for Issuing Fatwas ruled that making up the day was obligatory. However, if the error is based on astronomical calculations or mere conjecture, it holds no legitimate (Shar'i) weight.