Fasting: Keeping Recommended Fasts in Medina for a Traveller
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1687
A traveller can keep recommended fasts in Medina for three days for the fulfilment of wishes [i.e. for particular needs (ḥājāt) of his to be granted]; and the obligatory precaution is for those three days to be Wednesday, Thursday, and Friday.