1JDAY(1)                               2.4                              JDAY(1)
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NAME

6       jday, j2d - astronomical julian date conversion utilities
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SYNOPSIS

9       jday
10
11       jday [-d [-]year-mm-dd hh:mm:ss]
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13       jday [--version]
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15       jday [--h[elp]]
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17       j2d <julian decimal date>
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19       j2d [--version]
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21       j2d [--h[elp]]
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DESCRIPTION

24       jday  and  j2d  are command line utilities to convert calendar dates to
25       astronomical julian dates, and julian dates to calendar  dates.   There
26       is  a  corresponding  library  libjday.a which can be used for the same
27       functionality within applications.
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OPTIONS

30       jday accepts the following options:
31
32       none at all
33               jday will simply print out the julian date based  on  the  date
34               and time found on the system.
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36       [year [month [day [hour [minute [second]]]]]]
37               Always  in that order, to override that value found on the sys‐
38               tem.
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40       -d [-]year-mm-dd hh:mm:ss
41               Specify a year in the same format as that printed out by j2d
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43       j2d accepts the following options:
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45       <julian decimal date>
46               This is the only, and required argument to j2d
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48       both commands accept the following options:
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50       --version
51               Display the version of the programs.
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53       --h[elp]
54               Display a command help message
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EXAMPLES

57       $ jday 1970 1 1 12 0 0
58       2440588.000000
59       $ jday 0 1 1 12 0 0
60       1721058.000000
61       $ jday -4712 1 1 12 0 0
62       0.000000
63       $ jday -d -4712-01-01 12:00:00
64       0.000000
65       $ j2d 0.0
66       -4712-01-01 12:00:00
67       $ j2d 1721058.0
68       0-01-01 12:00:00
69       $ j2d 2440588.0
70       1970-01-01 12:00:00
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SEE ALSO

73       Time Standard: http://tycho.usno.navy.mil
74       Systems of time:  http://tycho.usno.navy.mil/systime.html
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77       Copyright ©  1986-2005, Hiram Clawson
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79       jday at hiram.ws
80
81       All rights reserved.
82
83       Redistribution and use in source and binary forms, with or
84               without modification, are permitted provided that the following
85               conditions are met:
86
87       Redistributions of source code must retain the above
88               copyright  notice,  this  list  of conditions and the following
89               disclaimer.
90
91       Redistributions in binary form must reproduce the
92               above copyright notice, this list of conditions and the follow‐
93               ing disclaimer in the documentation and/or other materials pro‐
94               vided with the distribution.
95
96       Neither name of The Museum of Hiram nor the names of
97               its contributors may be used to  endorse  or  promote  products
98               derived  from this software without specific prior written per‐
99               mission.
100
101       THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
102               CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR  IMPLIED  WARRANTIES,
103               INCLUDING,  BUT  NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER‐
104               CHANTABILITY AND FITNESS FOR  A  PARTICULAR  PURPOSE  ARE  DIS‐
105               CLAIMED.   IN  NO  EVENT  SHALL  THE REGENTS OR CONTRIBUTORS BE
106               LIABLE FOR ANY DIRECT,  INDIRECT,  INCIDENTAL,  SPECIAL,  EXEM‐
107               PLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
108               PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
109               OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
110               THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,  OR
111               TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
112               OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
113               OF SUCH DAMAGE.
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117Version                         10 October 2005                        JDAY(1)
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