Generally, men should take a head bath every day; and it is a must when a man’s father is no more. Some would say that school-going children, children who go for Veda adhyayanam, need not take daily head baths while they are bachelors. The stipulations after the demise of a mother are not applicable here.
It is considered special to take an oil bath on Saturdays. For women it is Fridays. Oil baths must not be taken on days of fasting, Amavasyai, Ekadasi, Paurnami. An important aspect of an oil bath is that it must be taken only after 8 AM and after the performance of Sandhyavandanam and not before.