Praise be to Allah.
The one who forgets one of the three days does not have to do anything if he fasts it after he returns home.
And Allah is the source of strength; may Allah send blessings and peace upon our Prophet Muhammad and his family and Companions. End quote.
Standing Committee for Academic Research and Issuing Fatwas.
Shaykh ‘Abd al-‘Azeez ibn ‘Abd-Allaah ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan, Shaykh ‘Abd-Allaah ibn Qa’ood