JDymd: Julian Day from yyyy, mm, dd

In insol: Solar Radiation

Description

Computes Julian Day from a given date.

Usage

JDymd(year,month,day,hour=12,minute=0,sec=0)

Arguments

year	numeric year
month	1-12: number of the month.
day	1-31: day of the month.
hour	0-23: hour of the day.
minute	0-59: minutes.
sec	0-59: seconds.

Value

Julian Day, or number of days since January 1, 4713 BCE at noon UTC.

Warning

This simplification is only valid between 1901 and 2099. To get correct values it is recommended to increase the number of digits to display: options(digits=12)

Note

You may like to double check the results here:
https://ssd.jpl.nasa.gov/tc.cgi

Author(s)

Javier G. Corripio

References

Danby, J. M. Eqn. 6.16.4 in Fundamentals of Celestial Mechanics, 2nd ed. Richmond, VA: Willmann-Bell, p. 207, 1988.

See Also

JD

Examples

JDymd(2019,3,20,12)

print(paste('Number of days since the beginning of the century (1/1/2001):',
	JD(Sys.time())-JDymd(2001,1,1,0)))

Example output

[1] 2458563
[1] "Number of days since the beginning of the century (1/1/2001): 7402.70721319364"

insol documentation built on Feb. 10, 2021, 5:08 p.m.