Seollal
Lunar New Year is the first day of the Chinese calendar, which is a lunisolar calendar mainly used for traditional celebrations.
Elsewhere on timeanddate.com
Labor Day
Labor Day, International Workers' Day, and May Day, is a day off for workers in many countries around the world.
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?