Bad hair day
A day on which one's hair seems unmanageable. Also extended to mean a day when everything seems to go wrong.
This first came into prominence in the language following its use in the 1992 film Buffy the Vampire Slayer.
Buffy (Kristy Swanson) to the one-armed vampire Amilyn (Paul Reubens):
"I'm fine but you're obviously having a bad hair day.".
The phrase was already known by that date but not very widely used. In July 1988 the Press Democrat, a Santa Rosa, California newspaper printed:
"Even those who emerge from the sea to casually braid their shiny wet vines into a thick coil with a hibiscus on the end also have bad-hair days.".
Whether that's where the term was coined isn't certain, although it is a strong contender. There are many hearsay reports that it is much earlier, but no hard evidence has emerged to support them.
See other phrases that were coined in the USA.