Union holiday.
Had a good friend of my dad who was born on 4/1 - they worked together at a union job. You got like double time for working on union holidays - and same for working your birthday and time and a half for working weekends.
Never forget the story about how he managed to slip past the bosses and stay “working” one Saturday 4/1 for like 18 hours. The paycheck he drew for that single double was insane - basically making like what he would on a single workday every hour he worked with the time and a half multipled by 6 every hour. They made damn to never let that happen again.