Labor Day / May Day
Labor Day, International Workers' Day, and May Day, is a day off for workers in many countries around the world.
Elsewhere on timeanddate.com
Whit Sunday
Many Christians all over the world annually observe Pentecost, also known as Whitsunday or Whit Sunday.
AM and PM Explained
How does the 12-hour clock system work? Is midnight 12 am or 12 pm?
Daylight Saving Time (DST)
Why do many countries set the clocks back and forth an hour twice a year?