Question: Whenever it is suitable and you can without difficulty, you should wear the skullcap. For example, when you go to the Musjid or at an Islamic function, you should wear the skullcap. You will not be sinful for not wearing the skullcap all the time.
Assalamu Alaikum Wa Rahmatullahi Wa Barakaatuh
Wearing the skullcap for men is Sunnah and the hair of a male is not Aurah (part of the body which is necessary to conceal from non-Mahrams of the opposite gender). On the contrary, the hair of a female is Aurah and it is Fardh (obligatory) on a female to cover her hair when she emerges from home or is in the presence on non-Mahram males. And Allah Knows Best.
Mufti Suhail Tarmahomed