Today is the first Friday in March.
In the U.S., this is the "National Dress in Blue Day".
It's on the list of official national days in the U.S.:
https://nationaldaycalendar.com/national-dress-in-blue-day-first-friday-in-march/
It's when everybody there wears blue:
https://www.ccalliance.org/about/awareness-month/dress-in-blue-day
But ... do you know when and where this actually started? Do you know whose idea it was originally? Read this:
National Dress in Blue Day
https://www.colonclub.com/programs-support/blog/dress-blue-day