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The last ten nights of Ramadan begin from the night before the twenty first day, whether the month is thirty days or is twenty-nine days. The odd-numbered nights of the last ten of Ramadan are the nights before the twenty-first, twenty-third, twenty-fifth, twenty-seventh and twenty-ninth (day).

The majority of scholars agree that one should enter his place of I`tikaf before the sun sets on the night of the twenty-first and come out when the sun sets on the last day of Ramadan.