OFFSET
1,2
COMMENTS
The number of days elapsed since the Gregorian date Sunday, December 31, 1 BC is also called the 'absolute date'. Note that there was no year 0. Thus this sequence shows the absolute date of the New Year's Day of the year n.
LINKS
Peter Luschny, Table of n, a(n) for n = 1..3000
Peter Luschny, Calendars, Conversions of Dates, Change of Calendars, GitHub 2022.
John Walker, Calendar Converter.
Wikipedia, Gregorian calendar.
FORMULA
From Robert B Fowler, Aug 20 2024: (Start)
a(n) = 1 + 365*m + floor(m/4) - floor(m/100) + floor(m/400), where m = n-1.
a(n+400*k) = a(n) + 146097*k. (End)
EXAMPLE
Gregorian date 1/1/2022 = Julian date 12/19/2021 = Hebrew date 10/28/5782 = Islamic date 5/27/1443 = absolute date 738156.
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Jan 02 2022
STATUS
approved