بسم الله الرحمن الرحيم
(Fatwa: 1494/1153/B=11/1434)
One should wear the cap / topi every time except sleeping and bathing. It is against the dignity to remain without topi. Cap has always been the cloth of esteemed people.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband
