bad hair day
A day on which everything seems to go wrong
I knew it was going to be a bad hair day when I couldn't find my keys in the morning.
get up on the wrong side of the bed
Begin the day feeling unhappy and uncomfortable
What's got into Ben today? Did he get up on the wrong side of the bed?
make someone's day
Winning the lottery really made my day.
I've/We've Seen better days.
If something or someone has seen better days, they are not in such a good condition as they used to be.
Very hot days during summer
It's hard to get much work done during the dog days.