.Nd displays a calendar
.Sh SYNOPSIS
.Nm cal
-.Op Fl mjy
+.Op Fl mjy13
.Op Ar month Op Ar year
.Sh DESCRIPTION
.Nm Cal
the current month is displayed.
The options are as follows:
.Bl -tag -width Ds
+.It Fl 1
+Display single month output (use if cal was built with -3 as default to get
+older traditional output)
+.It Fl 3
+Display prev/current/next month output (use if cal was built with traditional
+-1 as default to get newer improved output)
.It Fl m
Display Monday as the first day of the week.
(The default is Sunday.)