Re: Julian Day Calculation - Plea for Help
- To: mathgroup at smc.vnet.net
- Subject: [mg3967] Re: Julian Day Calculation - Plea for Help
- From: ianc (Ian Collier)
- Date: Mon, 13 May 1996 01:47:05 -0400
- Organization: Wolfram Research, Inc.
- Sender: owner-wri-mathgroup at wolfram.com
In article <searchme-2904961319480001 at 204.250.36.184>,
searchme at earthlink.net (Matthew K.) wrote:
> Hi,
>
> Please forgive me if this is a duplicate posting - I tried posting
> yesterday and while it appeared to post, I was having a great deal of
> trouble with my server and it now appears that this did not post at all.
> <sigh> Sorry for any inconvenience if it *does* appear mysteriously
> tomorrow.
>
> I need , if possible, to get the equation for calculating the Julian Day
> well into the future (we're talking 1000 years here). I have been unable
> to come up with an equation on the Web (limited at least in part by my
> wonderful but antique Mac Plus <grin>).
>
> If anyone can help me, it would be most appreciated. Please e-mail if you
> would at searchme at earthlink.net as I seldom check this group, not being a
> professional in this field. And if it is not something that can be easily
> calculated (requires an algorithm or something along those lines), could
> someone please let me know that?? Thanks so much for any assistance.
>
> Lisa
> --
> emergency address only: SMS CDs @aol.com
These conversions can be done using Mathematica's CalendarChange
function, which is defined in Miscellaneous`Calendars`, one of
the standard packages distributed with Mathematica. if you want
to see how it is implemented yopu can simply open the package with
a text editor and examine the Mathematica code.
Here is an example (using a date 1000 years in the future):
In[4]:=
Needs[ "Miscellaneous`Calendar`" ]
In[5]:=
?CalendarChange
CalendarChange[date, calendar1, calendar2] converts a date
in calendar1 to a date in calendar2.
In[6]:=
CalendarChange[ {2996, 5, 6}, Gregorian, Julian ]
Out[6]=
{2996, 4, 16}
I hope this helps.
--Ian
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Ian Collier
Wolfram Research, Inc.
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tel:(217) 398-0700 fax:(217) 398-0747 ianc at wolfram.com
Wolfram Research Home Page: http://www.wolfram.com/
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