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**Yesterday **(21 September 2019)** minus 14 years** will be

21st September 2005

For example

- What is 21 days before Today? (Today minus 21 days)
- What is 100 years before 9 August 2025? (9 August 2025 minus 100 years)
- What is 90 months before Yesterday? (Yesterday minus 90 months)
- What is 200 weeks from 25 May 2022? (25 May 2022 plus 200 weeks)
- What is 4 days before Tomorrow? (Tomorrow minus 4 days)
- What is 100 years before 24 October 2023? (24 October 2023 minus 100 years)

The **Gregorian calendar** is the most widely used internationally civil calendar. It is named after Pope Gregory 13th, who introduced it in **October 1582**.

The Gregorian calendar is a **solar calendar**. A regular Gregorian year consists of 365 days, but as in the Julian calendar, in certain years, a leap year, a **leap day is added to February**

The months of **April, June, September, and November** have **30 days**, while the **rest have 31 days** except for **February**, which has **28 days** in a standard year, and **29 in a leap year**.

For best results, please use dates after 1752 and **verify any data** if you are doing genealogy research.