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**21 October 2018**** plus 120 days** will be

18th February 2019

For example

- What is 21 years before Today? (Today minus 21 years)
- What is 20 months before 28 March 2023? (28 March 2023 minus 20 months)
- What is 800 years before Yesterday? (Yesterday minus 800 years)
- What is 500 years before 26 January 2024? (26 January 2024 minus 500 years)
- What is 30 years from Tomorrow? (Tomorrow plus 30 years)
- What is 9 weeks from 14 July 2024? (14 July 2024 plus 9 weeks)

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.