Civil time is occasionally adjusted by one second increments called leap seconds. A detailed explanation of what a second actually is, and why leap seconds are necessary.

Lots of time and date related information, such as yearly and monthly calendars, counters, countdown, and the world clock which shows the current time in cities all over the world.

The calendar was the center of Maya life and their greatest cultural achievement. To carry out their astronomical calculations they developed a sophisticated mathematical system. The Maya Calendar website is developing with the intent of providing a complete view of Maya culture.