Julian date format

[Rick Elliott]

I have a user who is in the process of writing a script and needs to convert the date values he has into Julian Date format. Therefore if he enters March 10th he needs to know what the Julian date value would be. Obviously I can get the current value using date +%j but I need to calculate the value based on whatever date is entered, can anybody assist on this matter, is there an esay way of doing this.

[Rodney Hills]

Clay has a neat tool called caljd.sh,

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xea948cc5e03fd6118fff0090279cd0f9,00.html

(I found the link by using the "search" capability of the forum and plugging in "julian" for the keyword...)

-- Rod Hills

[Pete Randall]

Rick,

You need to look into Clay's "date hammer". Try these:
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x60e65e938a10d6118ff40090279cd0f9,00.html
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xce87107d277ad611abdb0090277a778c,00.html
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x7d8c107d277ad611abdb0090277a778c,00.html

[A. Clay Stephenson · Accepted solution]

Hi Rick:

The julian date returned by date '+%j' is NOT a Julian date. Julian days are used by astronomers to count days sequentially from ~4713BCE. The good news is that the attached script will do julian days and can convert month, day, year to a julian day and will convert a julian day to month, day, year.

Caljd.sh -u will give full usage.

Simple example:

caljd.sh 9 15 2002
will output 2452533

caljd.sh 2452533
will output 09 15 2002