perpetual calendar
Definition
- Noun:
- A chart or mechanical device that shows the day of the week for any given date (day, month, year) over a very long span of years, often many decades or centuries.
Usage
- A perpetual calendar is used to find past or future weekdays without needing a separate calendar for each year. It accounts for the variations in the Gregorian calendar, including leap years.
- It can be a physical object, like a rotating paper chart, a slide rule, or a sophisticated feature in a watch or clock that automatically adjusts for month lengths and leap years.
Examples
- Noun:
- The historian used a perpetual calendar to determine that the famous battle took place on a Tuesday.
- This wristwatch has a perpetual calendar complication that won't need manual adjustment until the year 2100.
- You can find online perpetual calendars that calculate the day of the week for any date between 1800 and 2200.
Advanced Usage
- In horology (the study of timekeeping), a perpetual calendar is a complex mechanism in a timepiece that correctly displays the date, day, month, and often moon phases, accounting for different month lengths and leap years automatically.
- Collectors value watches with a perpetual calendar for their engineering precision.
Variants and Related Words
- Calendar (n): A system for organizing and measuring time over periods like days, months, and years.
- Perpetual (adj): Never ending or changing; permanent. (This explains the "perpetual" in "perpetual calendar"—it works for a seemingly endless period).
Synonyms
- Perpetual almanac: An older, less common term with the same meaning.
- World calendar: (Note: This is a concept; it refers to a proposed reform of the Gregorian calendar, not a device for finding weekdays).
Related Phrases
- To consult a perpetual calendar: To use a perpetual calendar to look up information.
- To plan the event, she consulted a perpetual calendar to avoid scheduling it on a weekend.
Noun
-
a chart or mechanical device that indicates the days of the week corresponding to any given date over a long period of years
