Ayyamul Bidh fasting is sunnah fasting which is done in the middle of the month. The time of fasting Ayyamul Bidh is based on the qomariah calendar. You can't determine when this fast starts through the Islamic calendar. The exact time is every 13-15 every month of Hijri. Except when it coincides with the holy day. Then fasting on that date is prohibited. The law of fasting Ayyamul Bidh is sunna. The procedure for fasting Ayyamul Bidh is the same as other fasting, starting from the dawn and breaking the fast when the Adhrib Maghrib reverberates. There is also the intention is as follows: