AM and PM Explained
How does the 12-hour clock system work? Is midnight 12 am or 12 pm?
Elsewhere on timeanddate.com
17th of Tammuz
The 17th day of the Jewish month of Tammuz is a day of mourning to mark the anniversary of five calamities that befell the Jewish people. It is known as the Fast of Shiva Asar B'Tammuz.
Daylight Saving Time (DST)
Why do many countries set the clocks back and forth an hour twice a year?
12 Months of the Year
The 12 months of the year are linked to the Moon's orbit around Earth. Why are there 12 months? What do the month names mean?