.TH LUNAR 1 "15 May 2020" "Lunar version 2.2-7 (Debian)"
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.SH NAME
lunar \- a calendar conversion utility
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.SH SYNOPSIS
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.SY lunar
.OP \-usthg5b
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.SY lunar
.OP \-usthg5b
.I year
.I month
.I day
.RI [ hour ]
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.SY lunar
.OP \-usthg5b
.B \-i
.OP \-l
.I year
.I month
.I day
.RI [ hour ]
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.SY lunar
.B \-\-help
.YS
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.SH DESCRIPTION
The
.I lunar
program performs date conversion between the Gregorian Solar Calendar (SC)
and the Chinese Lunar Calendar (LC).
Given a date in either calendar, the program also
outputs the corresponding "\fIsheng\%xiao\fR" (animal of the year)
and "\fIganzhi\fR" characters.
The date range currently covered is from about 1900 A.D. to 2049 A.D.
.PP
For the sake of convenience, we choose the convention such that the solar 
and lunar year numbers of the first day of a lunar year are the same.
For example, SC 1991.2.15 is LC 1991.1.1,
while SC 1991.2.14 is LC 1990.12.30.
Moreover, we choose the convention such that the solar and lunar hour numbers
(in 24-hour clock) of a date are the same, although a lunar day starts
at 23:00 of a solar day. This means that SC 1991.2.15.23 is LC 1991.1.2.23,
while SC 1991.2.16.0 is LC 1991.1.2.0,
and SC 1991.2.16.1 is LC 1991.1.2.1.
.PP
The standard time of the Lunar Calendar is
Beijing (Hong Kong) Standard Time, not GMT.
Be sure to adjust appropriately for other time zones
and "Daylight Saving Time".
.PP
In the Lunar Calendar,
a normal year has 12 months, and a leap year (run-nian) has 13 months,
where the extra month is called a "leap month" (run-yue).
For example, the leap month that follows immediately the 6-th lunar month
is called the 6-th leap month.
A (leap) month is either a short or long one, which has 29 or 30 days
respectively.
.PP
There are 10 \fIgan\fR's and 12 \fIzhi\fR's.
The \fIganzhi\fR labeling of the year, month, day and hour of a date
is a member of the Cartesian product GxGxGxG, where G = {1,2,...,60}.
For example, "\fIjia-zi\fR" is 1, "\fIyi-chou\fR" is 2, and so on.
The \fIganzhi\fR of the j-th leap month is the same as that of the j-th month.
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.SH OPTIONS
.P
Since
.I lunar
was first packaged for Debian in 2002, the Debian package maintainer
has made minor additions such as Big5 and UTF-8 support.
More recently,
.I lunar
gained the ability to detect system locale and choose the correct
character set.
.P
.I Lunar
now also detects and displays the current China Standard Time by default,
so that the
.I year
.I month
.I day
.RI [ hour ]
parameters are now optional for solar-to-lunar calendar conversion.
.P
The possible options are
.TP
.B \-b
output \fIganzhi\fR in special "bitmap" characters.
.TP
\fB\-u\fR, \fB\-\-utf8\fR
output \fIhanzi\fR or Chinese characters encoded in UTF-8.
.TP
.B \-s
output simplified Chinese (for UTF-8 only).
.TP
.B \-t
output traditional Chinese (for UTF-8 only).
.TP
\fB\-g\fR, \fB\-h\fR, \fB\-\-gb\fR
output \fIhanzi\fR or Chinese characters encoded in (highest-bit-set) GB code.
.TP
\fB\-5\fR, \fB\-\-big5\fR
output \fIhanzi\fR or Chinese characters encoded in Big5.
.TP
.B \-i
convert a lunar date to solar date.
The default is to convert a solar date to a lunar date.
.TP
.B \-l
indicate the month is a lunar leap month.
This option is meaningful only when the "\-i" option is used.
.TP
.B \-\-help
Print a help message.
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.SH COPYRIGHT
Copyright (C) 1988, 1989, 1991, 1992, 2001 Fung F. Lee and Ricky Yeung 
.sp
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

The last version of this program was released on July 23, 1992 as
version 2.1a.  This program was first released under the terms of 
GNU GPL on October 28, 2001 as version 2.2. Both versions are identical
except for the license text.

.SH AUTHORS
Fung F. Lee and Ricky Yeung
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.SH ACKNOWLEDGEMENT
The special "bitmap" file "lunar.bitmap" was contributed by Weimin Liu.

Special thanks to Hwei Chen Ti who extended the tables from 2001 to 2049.
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.SH BUGS
Bug reports and comments should be sent to lee@umunhum.stanford.edu.
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.SH DISCLAIMER
This software has no connection with our employers.