Western New Year's Day
New Year’s Day is the first day of the year, or January 1, in the Gregorian calendar.
Elsewhere on timeanddate.com
AM and PM Explained
How does the 12-hour clock system work? Is midnight 12 am or 12 pm?
First Day of Eid al-Adha
Eid al-Adha (Id ul-Adha) is an Islamic festival falling on the 10th day of the month of Dhul Hijja (Thou al-Hijja) to commemorate the willingness of Ibrahim (Abraham) to sacrifice his son.
Daylight Saving Time (DST)
Why do many countries set the clocks back and forth an hour twice a year?