T: /* From date to Short Julian day */

2018-12-03T11:52:53Z

From date to Short Julian day

T: /* From date to Short Julian day */

2018-12-03T11:52:13Z

From date to Short Julian day

Maintenance script at 22:05, 30 November 2018

2018-11-30T22:05:37Z

New page

[[Short Julian day]] is the same as [[Reduced Julian Day]] and [[Modified Julian day]]
<ref>
http://www.csgnetwork.com/julianmodifdateconv.html
Modified Julian Day Converter
</ref>
and refers to scale of [[time]], related with rotation of orientation of the Earth with respect to Sun.

Short julian days are related to date, expressed with year.mo.da.
At least since 1858.11.16, the short Julian day is positive, and is related to the convencional civil data with the simple algorithms copypasted below:

==From date to Short Julian day==

<poem><nomathjax><nowiki>
void ju24da(int Mjd, int *Year, int *Month, int *Day)
{ int J, C, Y, M;
J = Mjd + 2400000 + 68569;
// J = Mjd + 2400001 + 68569;
// J = Mjd + 68569;
C = 4 * J / 146097;
J = J - (146097 * C + 3) / 4;
Y = 4000 * (J + 1) / 1461001;
J = J - 1461 * Y / 4 + 31;
M = 80 * J / 2447;
*Day = J - 2447 * M / 80;
J = M / 11;
*Month = M + 2 - (12 * J);
*Year = 100 * (C - 49) + Y + J;
// http://www.leapsecond.com/tools/gpsdate.c
}

</nowiki></nomathjax></poem>

==From date to Short Julian day==

<poem><nomathjax><nowiki>
int daju24(int Y,int M, int D)
{ int a, y,m;
a=(14-M)/12;
y=Y+4800-a;
m=M+12*a-3;
// return D + (153*m+2)/5 +365*y + y/4 - y/100 + y/400 -32045 - 2400001;
return D + (153*m+2)/5 +365*y + y/4 - y/100 + y/400 -32045 - 2400000;
}
</nowiki></nomathjax></poem>

==Julian day==

Usually, the Julian day is used instead of the [[Short Julian day]].
At least for positive values of the Short Julian day, denoted with SUD, the Julian day can be expressed as follows:

Julian day = SUD + 2400000

Short Ulian day is easier to copy past for those persons, who can count 5 digits, but may fail, counting 7 digits..
In additoin, SUD may have also nevative values, and the simple formulas in the algorithms above hold.
As for the Julian days, for small and negative values, the results by the algorithms above differ from those, suggested by the public service
<ref>
http://www.nr.com/julian.html?delta=++240000 Julian Day and Civil Date Calculator
</ref><ref>
http://aa.usno.navy.mil/data/docs/JulianDate.php
Julian Date Converter
</ref>.

The main purpose of the Short Julian day is the same as that of the conventional Julian day, namely, calculation of time interval between given data and calculation of date after given number of days since the given data.

There are many various modifications of the Julian days, but, perhaps, in TORI, Short Julian days will be used.

==References==
<references/>

http://en.wikipedia.org/wiki/Julian_day

==Keywords==
[[History]],
[[Time]]

[[Category:English]]
[[Category:History]]
[[Category:Time]]

@@ Line 31: / Line 31: @@
 </nowiki></nomathjax></poem>
-==From date to Short Julian day==
+==From date to [[Short Julian day]]==
 <poem><nomathjax><nowiki>

Short Julian day - Revision history

T: /* From date to Short Julian day */

T: /* From date to Short Julian day */

Maintenance script at 22:05, 30 November 2018