Muslim feasts are timed according to local sightings of various phases of the moon and the dates given above are approximations. During the lunar month of Ramadan that precedes Eid al-Fitr, Muslims fast during the day and feast at night and normal business patterns may be interrupted. Many restaurants are closed during the day and there may be restrictions on smoking and drinking. Some disruption may continue into Eid al-Fitr itself. Eid al-Fitr and Eid al-Adha may last anything from two to 10 days, depending on the region.