.\"	$OpenBSD: cal.1,v 1.33 2024/07/31 17:09:23 jmc Exp $
.\"	$NetBSD: cal.1,v 1.6 1995/09/02 05:34:20 jtc Exp $
.\"
.\" 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.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)cal.1	8.2 (Berkeley) 4/28/95
.\"
.Dd $Mdocdate: July 31 2024 $
.Dt CAL 1
.Os
.Sh NAME
.Nm cal
.Nd displays a calendar
.Sh SYNOPSIS
.Nm cal
.Op Fl jmwy
.Op Ar month
.Op Ar year
.Sh DESCRIPTION
.Nm
displays a simple calendar.
Calendars may be displayed by month or by year.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl j
Display Julian dates (days one-based, numbered from January 1).
The options
.Fl j
and
.Fl w
are mutually exclusive.
.It Fl m
Display weeks starting on Monday instead of Sunday.
.It Fl w
Display week numbers in the month display.
If
.Fl m
is specified, the ISO week format is assumed.
The options
.Fl j
and
.Fl w
are mutually exclusive.
.It Fl y
Display a calendar for the current year.
.El
.Pp
A single numerical parameter specifies the
.Ar year
(1 \- 9999)
to be displayed.
The year must be fully specified:
.Dq Li cal 89
will
.Em not
display a calendar for 1989.
Two parameters denote the
.Ar month
(1 \- 12, or a month name or abbreviation thereof)
and
.Ar year .
Alternatively,
a single parameter may be given specifying
the name or abbreviated name of a month:
in that case a calendar is displayed for that month of the current year.
If no parameters are specified, the current month's calendar is
displayed.
.Pp
A year starts on January 1st.
.Pp
The Gregorian Reformation is assumed to have occurred in 1752 after the 2nd
of September.
By this time, most countries had recognized the Reformation (although a
few did not recognize it until the early 1900s).
Eleven days following that date were eliminated by the Reformation, so the
calendar for that month is a bit unusual.
.Sh EXIT STATUS
.Ex -std cal
.Sh SEE ALSO
.Xr calendar 1
.Sh STANDARDS
The
.Nm
utility is compliant with the
X/Open System Interfaces option of the
.St -p1003.1-2024
specification.
.Pp
The flags
.Op Fl jmwy ,
as well as the ability to specify a month name as a single argument,
are extensions to that specification.
.Pp
The week number computed by
.Fl mw
is compliant with the
.St -iso8601
specification.
.Sh HISTORY
A
.Nm
command appeared in
.At v1 .