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🗓️ History of the Gregorian Calendar
The Gregorian calendar, the one most of the world uses today, consists of 365 days in a regular year and 366 in a leap year, with the extra day added to February. Most months have either 30 or 31 days, except for February, which has 28 days in standard years and 29 in leap years. Days Calculator
This calendar evolved from the Julian calendar, which itself was a revision of the ancient Roman calendar—originally a lunar-based system with only 10 months and about 304 days. That left an unstructured winter period, causing seasonal misalignment over time.
To correct this, the Roman Republican calendar was introduced, influenced by Greek astronomical systems. It calculated months based on 29.5-day lunar cycles and attempted to align with the solar year using extra (intercalary) months.
Then came Julius Caesar’s reform in 46 BC, which introduced the Julian calendar. It was solar-based, with 365 days and an extra day added every four years (leap year). However, it overestimated the solar year by about 11 minutes annually. That small error compounded over centuries.
By 1582, the calendar had drifted 10 days off. Pope Gregory XIII addressed this by:
- Skipping 10 days (Oct 4 → Oct 15, 1582),
- Modifying leap year rules: Century years are only leap years if divisible by 400.
This new system—the Gregorian calendar—was far more accurate, accumulating an error of only 1 day every 3,030 years. It took centuries to be fully adopted but is now the global standard.
🎉 Holidays: Meaning and Modern Use
A holiday is a day when typical routines—like school or work—are paused or reduced. However, the term’s meaning varies by region. For example:
- In the U.S., holidays refer to national, religious, or cultural days off, while “vacation” refers to personal leave.
- In the UK and some former British colonies, “holiday” may refer to both public holidays and personal vacation days.
Holidays often honor historical events, people, or traditions. Some are globally observed, like New Year’s Day or Christmas, while others are specific to nations or cultures.
The way holidays are observed can also vary:
- Some holidays result in complete closures of businesses and schools.
- Others offer partial breaks or special business hours.
- In countries like Brazil, Carnaval nearly shuts down regular life for a week.
🏛️ U.S. Federal Holidays
This calendar supports U.S. federal holidays, which are recognized by the federal government. On these days:
- Non-essential federal offices are closed.
- Federal employees get paid leave.
Private sector observance is up to individual employers. Some may offer holiday pay for those working on such days.
📅 Fixed vs Floating Holidays
- Fixed holidays fall on the same date every year (e.g., Christmas – Dec 25).
- Floating holidays vary by year (e.g., Thanksgiving – 4th Thursday in November).
🇺🇸 U.S. Federal Holidays (2025 & 2026)
| Holiday | 2025 Date | 2026 Date |
|---|---|---|
| New Year’s Day | Jan 1, 2025 | Jan 1, 2026 |
| Martin Luther King Jr. Day | Jan 20, 2025 | Jan 19, 2026 |
| President’s Day | Feb 17, 2025 | Feb 16, 2026 |
| Memorial Day | May 26, 2025 | May 25, 2026 |
| Juneteenth National Day | Jun 19, 2025 | Jun 19, 2026 |
| Independence Day | Jul 4, 2025 | Jul 4, 2026 |
| Labor Day | Sep 1, 2025 | Sep 7, 2026 |
| Columbus Day | Oct 13, 2025 | Oct 12, 2026 |
| Veterans Day | Nov 11, 2025 | Nov 11, 2026 |
| Thanksgiving Day | Nov 27, 2025 | Nov 26, 2026 |
| Christmas Day | Dec 25, 2025 | Dec 25, 2026 |