not be somebody's day

be not (one's) day

To be a day that has been particularly stressful, difficult, disappointing, or filled with unfortunate events. I can't believe I got locked out of the apartment. This isn't my day. I'm sorry, sweetie, I know you studied hard for that test. It just wasn't your day.
See also: not
Farlex Dictionary of Idioms.

not be somebody’s ˈday

(spoken) be a day when a lot of things go wrong for somebody: First I tore my jacket, then my car broke down. This is definitely not my day!
See also: not
Farlex Partner Idioms Dictionary
See also:
  • be not (one's) day
  • not (one's) day
  • not one's day, this is
  • not someone's day
  • the evil hour/day/moment
  • put (one) through it
  • put somebody through it
  • If it's not one thing, it's another!
  • be music to (one's) ears
  • be music to your ears