GUIDES
Guides
Plain-language explanations of how calendars and dates actually work.
- What Is a Leap Year?
Why leap years exist, how to identify one, and which years are leap years.
- How Is the Day of the Week Calculated?
The logic behind finding any date's weekday, from ancient dates to the far future.
- How Many Days Are Left in the Year?
How day-of-year counts and remaining-days figures are calculated.
- Calendar Year vs. Fiscal Year: What's the Difference?
How a fiscal year differs from the standard calendar year, and why countries vary.
- How Often Does a Calendar Repeat?
When a full 12-month calendar layout matches another year exactly, and why.