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**Tomorrow **(20 May 2019)** minus 90 years** will be

20th May 1929

For example

- What is 100 years before Today? (Today minus 100 years)
- What is 365 weeks from 29 April 2023? (29 April 2023 plus 365 weeks)
- What is 800 days before Yesterday? (Yesterday minus 800 days)
- What is 9 weeks from 23 March 2021? (23 March 2021 plus 9 weeks)
- What is 20 weeks before Tomorrow? (Tomorrow minus 20 weeks)
- What is 9 years before 30 August 2024? (30 August 2024 minus 9 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.