CALENDAR - CLICK HERE TO OPEN
A calendar is
a system of organizing days for social, religious, commercial or
administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. A date is
the designation of a single, specific day within such a system. Periods
in a calendar (such as years and months) are usually, though not
necessarily, synchronized with the cycle of the sun or the moon.
Many civilizations and societies have devised a calendar, usually
derived from other calendars on which they model their systems, suited
to their particular needs.
A full calendar system has a different calendar date for every day. Thus the week cycle is by itself not a full calendar system; neither is a system to name the days within a yearwithout a system for identifying the years.
The simplest calendar system just counts time periods from a reference date. This applies for the Julian day or Unix Time.
Virtually the only possible variation is using a different reference
date, in particular one less distant in the past to make the numbers
smaller. Computations in these systems are just a matter of addition and
Other calendars have one (or multiple) larger units of time.
Calendars that contain one level of cycles:
- week and weekday – this system (without year, the week number keeps on increasing) is not very common
- year and ordinal date within the year,