Once the crescent of Ramadan is sighted anywhere and that sighting is established by a valid witness, fasting becomes obligatory upon all Muslims. Local horizons are not considered after a confirmed sighting has been reported.

Simply resolving in one’s heart that “I will fast tomorrow for Ramadan” is sufficient.

In the Hanbali school, a separate, specific intention is required for each day of obligatory fasting in Ramadan, and it must be made during the night i.e. between the adhan of Maghrib and the adhan of Fajr .