.\" Copyright (c) 1989, 1990, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Kim Letkeman.
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.\" modification, are permitted provided that the following conditions
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.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
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.\"     @(#)cal.1	8.1 (Berkeley) 6/6/93
.\"
.Dd June 6, 1993
.Dt CAL 1
.Os
.Sh NAME
.Nm cal
.Nd displays a calendar
.Sh SYNOPSIS
.Nm cal
.Op Fl smjy13
.Op [ [ Ar day ] Ar month ] Ar year
.Sh DESCRIPTION
.Nm Cal
displays a simple calendar.
If arguments are not specified,
the current month is displayed.
The options are as follows:
.Bl -tag -width Ds
.It Fl 1
Display single month output.
(This is the default.)
.It Fl 3
Display prev/current/next month output.
.It Fl s
Display Sunday as the first day of the week.
.It Fl m
Display Monday as the first day of the week.
.It Fl j
Display Julian dates (days one-based, numbered from January 1).
.It Fl y
Display a calendar for the current year.
.It Fl V
Display version information and exit.
.El
.Pp
A single parameter specifies the year (1 - 9999) to be displayed;
note the year must be fully specified:
.Dq Li cal 89
will
.Em not
display a calendar for 1989.
Two parameters denote the month (1 - 12) and year.
Three parameters denote the day (1-31), month and year,
and the day will be highlighted if the calendar is displayed on a terminal.
If no parameters are specified, the current month's calendar is
displayed.
.Pp
A year starts on Jan 1. The first day of the week is determined by the locale.
.Pp
The Gregorian Reformation is assumed to have occurred in 1752 on the 3rd
of September.
By this time, most countries had recognized the reformation (although a
few did not recognize it until the early 1900's.)
Ten days following that date were eliminated by the reformation, so the
calendar for that month is a bit unusual.
.Sh HISTORY
A
.Nm
command appeared in Version 6 AT&T UNIX.
.Sh OTHER VERSIONS
Several much more elaborate versions of this program exist,
with support for colors, holidays, birthdays, reminders and
appointments, etc. For example, try the cal from
http://home.sprynet.com/~cbagwell/projects.html
or GNU gcal.
.Sh AVAILABILITY
The cal command is part of the util-linux-ng package and is available from
ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.