Today is Tuesday, 2017/12/12.

• Why is the 1st day Day 0? The discrepancy is due to treating the dates as ordinal (1st, 2nd, 3rd, ...) and cardinal (0, 1, 2) numbers. It is equivalent to a person being age 0 during the first year of his life.

Date 1: Year :  Month :  Day : 
Date 2: Year :  Month :  Day : 

1974/07/24
Wednesday
⇒ ⇒ ⇒ 2017/12/12
Tuesday
Day 0
1st Day
⇒ ⇒ ⇒ Day 15,847
15,848th Day

 

Date : Year :  Month :  Day : 
N :   

2017-12-12
Tuesday
⇒ ⇒ ⇒ 2020-09-06
Sunday
2020-09-07
Monday
Day 0
1st Day
⇒ ⇒ ⇒ Day 999
1,000th Day
Day 1,000
1,001st Day

 

• This program is written in R (r-project.org).
    The "brew" package is used to integrate R and HTML.