It’s about time. We are now on Instagram!
a day when one cannot get a hairstyle to look good; by extension, a day on which everything seems to go wrong
The sort of day when nothing goes right; the sort of day that is not one's day: They had a bad hair day, a bad CD-ROM day, who knows?
[1990s+; fr the notion that one's well-being depends on whether one's hair looks good]