what is the etymology of the phrase mufdi day meaning you can wear casual clothes at work or school?

Answer 1

The word mufti, with a T rather than a D, was used in the British India Army to mean casual attire for military men. It was a sort of joking term used mostly in the 19th century, although I've seen it in a letter around 1903. The original Mufti was a Muslim legal expert and it's use for casual attire is thought to spring from his usual Oriental costume of dressing-gown, smoking cap (or fez) and carpet slippers.

Answer 2

It probably is derived from the arabic word 'mufti' which denotes a scholar (not a priest) in civilian clothes who is well-versed in his religion. Thus civilian clothes worn have come to mean informal dress. Hence a 'mufti day' is possibly a day when formal clothes give way to informal ones.

Answer 3

I've never heard that word, we just call it casual fridays, or something. Of course I wear shorts and a t shirt to work everyday, so it is casual day for me everyday.