Take the Work Out of Work, May 1
On the International Workers' Day (May 1) you will be awarded with the badge "Take the Work Out of Work". The requirement is that you record an activity during that day.
The country setting seems to affect this badge even if it is for an international day. I've tested numerous different country settings, but have only been successful with asian countries like Japan, Taiwan and India.
Take the Work Out of Work
Record an activity on International Workers' Day
Garmin Badge Database
Change country setting