bad hair day noun a day on which your hair is especially unruly; hence, a day on which nothing goes to plan US
They said I told them I was having a bad hair day. They didn’t even talk to me. (Quoting Gary Shandling) — SeattleTimes, p. 10, 25 January 1991
Ah, the bad hair day–where would chick lit or chauvinist revenge humour be without this contemporary cultural platitude? — TheTimes Magazine, p. 49, 31 May 2003