diff --git a/misc-utils/cal.1 b/misc-utils/cal.1
index fa79f914f..1ce0e2637 100644
--- a/misc-utils/cal.1
+++ b/misc-utils/cal.1
@@ -102,17 +102,23 @@ specified, the current month's calendar is displayed.
 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.
-.PP
 The week numbering depends on the first day of the week. If Sunday (the
 default) is used for the first day of the week, then the customary North
 American numbering will be used, i.e. first Sunday of the week starts the
 first week. If Monday is selected, then the ISO-8601 standard week numbering
 is used, where the first Thursday is in week number 1.
+.SH BUGS
+.PP
+The
+.B cal
+is using for Gregorian reformation the date of 1752 on the 3rd of
+September when it happen in Great Britain and it's colonies (including
+what is now the USA).  Ten days following that date were eliminated by
+the reformation, so the calendar for that month is a bit unusual.  The
+history when calendar reformation happen in different locales is ignored.
+.PP
+Alternative calendars, such as the Umm al-Qura, the Solar Hijri, the Ge'ez,
+or the lunisolar Hindu, are not supported.
 .SH HISTORY
 A cal command appeared in Version 6 AT&T UNIX.
 .SH AVAILABILITY