| Re: Julian Day Question [message #48874 is a reply to message #48873] |
Fri, 26 May 2006 07:17   |
David Fanning
Messages: 11724
Registered: August 2001
|
Senior Member |
|
|
Mike Wallace writes:
> I should have added that I always specify hours minutes and seconds when
> working with julday() for this very reason and because I specify the
> time within the day, I get what I expect. Come to think of it, julday()
> without the hours minutes and seconds also gives me what I expect
I'm going to think of it like this, which makes a weird
kind of sense to me:
If you specify ONLY a year, month, and day (in whatever
mixed up order you like [who wrote JULDAY, anyway!!]) then
clearly you must be concerned with a calendar DATE. So
having JULDAY return the date of the day that really
started at midnight is OK with me.
However, if you also specify the hour, minute, and second,
you must clearly be an astronomer (who else would care!?)
and JULDAY will return the astronomically correct Julian Day.
At least this is something I can remember...maybe.
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
