don't use stdio for error messages

[unix-history] / usr / src / usr.bin / cal / cal.1

.\" Copyright (c) 1989, 1990 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Kim Letkeman.
.\"
.\" %sccs.include.redist.man%
.\"
.\"     @(#)cal.1	6.8 (Berkeley) %G%
.\"
.Dd 
.Dt CAL 1
.Os
.Sh NAME
.Nm cal
.Nd displays a calendar
.Sh SYNOPSIS
.Nm cal
.Op Fl jy
.Op Ar month Op 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 j
Display julian dates (days one-based, numbered from January 1).
.It Fl y
Display a calendar for the current year.
.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.
If no parameters are specified, the current month's calendar is
displayed.
.Pp
A year starts on Jan 1.
.Pp
The Gregorian Reformation is assumed to have occurred
in 1972 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.  The
.Nm
command this man page describes is
derived from code contributed by Kim Letkeman.