Muslims who fast in Ramadan must generally have reached puberty.
In Islamic law, the Ramadan fast is generally obligatory for mentally competent Muslims who have reached puberty and are physically able to fast. Children who have not reached puberty are not normally required to observe the full obligation, although many gradually practice fasting for part of a day or occasionally join family fasts.
Puberty, rather than marriage, determines when this religious duty generally begins. Marriage is not a prerequisite, and a married person may still be exempt if illness, travel, pregnancy, breastfeeding, menstruation, old age, or another serious hardship makes fasting unsafe or impractical.
The daily fast runs from dawn until sunset. Those who miss fasts for temporary reasons may generally make them up later, while some people with permanent health limitations may follow other forms of religious compensation according to their interpretation and circumstances. Ramadan fasting is one of Islam’s Five Pillars.