1 files changed, 69 insertions, 17 deletions
diff --git a/usr.bin/calendar/calendar.1 b/usr.bin/calendar/calendar.1
index 404f44c..8f8fb5c 100644
--- a/usr.bin/calendar/calendar.1
+++ b/usr.bin/calendar/calendar.1
@@ -9,10 +9,6 @@
 .\" 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. All advertising materials mentioning features or use of this software
-.\"    must display the following acknowledgement:
-.\"     This product includes software developed by the University of
-.\"     California, Berkeley and its contributors.
 .\" 4. 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.
@@ -54,6 +50,8 @@
 .Ek
 .Oc
 .Op Fl W Ar num
+.Op Fl U Ar UTC-offset
+.Op Fl l Ar longitude
 .Sh DESCRIPTION
 The
 .Nm
@@ -93,6 +91,12 @@ as the default calendar file.
 .Sm on
 .Xc
 For test purposes only: set date directly to argument values.
+.It Fl l Ar longitude , Fl U Ar UTC-offset
+Only one is needed:
+Perform lunar and solar calculations from this longitude or from
+this UTC offset.
+If neither is specified, the calculations will be based on the
+difference between UTC time and localtime.
 .It Fl W Ar num
 Print lines from today and the next
 .Ar num
@@ -103,12 +107,36 @@ Ignore weekends when calculating the number of days.
 To handle calendars in your national code table you can specify
 .Dq LANG=<locale_name>
 in the calendar file as early as possible.
-To handle national Easter
-names in the calendars
-.Dq Easter=<national_name>
-(for Catholic Easter) or
-.Dq Paskha=<national_name>
-(for Orthodox Easter) can be used.
+.Pp
+To handle the local name of sequences, you can specify them as:
+.Dq SEQUENCE=<first> <second> <third> <fourth> <fifth> <last>
+in the calendar file as early as possible.
+.Pp
+The names of the following special days are recognized:
+.Bl -tag -width 123456789012345 -compact
+.It Easter
+Catholic Easter.
+.It Paskha
+Orthodox Easter.
+.It NewMoon
+The lunar New Moon.
+.It FullMoon
+The lunar Full Moon.
+.It MarEquinox
+The solar equinox in March.
+.It JunSolstice
+The solar solstice in June.
+.It SepEquinox
+The solar equinox in March.
+.It DecSolstice
+The solar solstice in December.
+.It ChineseNewYear
+The first day of the Chinese year.
+.El
+These names may be reassigned to their local names via an assignment
+like
+.Dq Easter=Pasen
+in the calendar file.
 .Pp
 Other lines should begin with a month and day.
 They may be entered in almost any format, either numeric or as character
@@ -122,11 +150,11 @@ Two numbers default to the month followed by the day.
 Lines with leading tabs default to the last entered date, allowing
 multiple line specifications for a single date.
 .Pp
-``Easter'', is Easter for this year, and may be followed by a positive
-or negative integer.
-.Pp
-``Paskha'', is Orthodox Easter for this year, and may be followed by a
-positive or negative integer.
+The names of the recognized special days may be followed by a
+positive or negative integer, like:
+.Dq Easter+3
+or
+.Dq Pashka-4 .
 .Pp
 Weekdays may be followed by ``-4'' ...\& ``+5'' (aliases for
 last, first, second, third, fourth) for moving events like
@@ -191,7 +219,8 @@ calendar file to use if no calendar file exists in the current directory.
 do not send mail if this file exists.
 .El
 .Pp
-The following default calendar files are provided:
+The following default calendar files are provided in
+.Pa /usr/share/calendars:
 .Pp
 .Bl -tag -width calendar.southafrica -compact
 .It Pa calendar.all
@@ -208,6 +237,8 @@ so that roving holidays are set correctly for the current year.
 Days of special significance to computer people.
 .It Pa calendar.croatian
 Calendar of events in Croatia.
+.It Pa calendar.dutch
+Calendar of events in the Netherlands.
 .It Pa calendar.freebsd
 Birthdays of
 .Fx
@@ -259,7 +290,28 @@ A
 .Nm
 command appeared in
 .At v7 .
+.Sh NOTES
+Chinese New Year is calculated at 120 degrees east of Greenwich,
+which roughly corresponds with the east coast of China.
+For people west of China, this might result that the start of Chinese
+New Year and the day of the related new moon might differ.
+.Pp
+The phases of the moon and the longitude of the sun are calculated
+against the local position which corresponds with 30 degrees times
+the time-difference towards Greenwich.
+.Pp
+The new and full moons are happening on the day indicated: They
+might happen in the time period in the early night or in the late
+evening.
+It doesn't indicate that they are starting in the night on that date.
+.Pp
+Because of minor differences between the output of the formulas
+used and other sources on the Internet, Druids and Werewolves should
+double-check the start and end time of solar and lunar events.
 .Sh BUGS
 The
 .Nm
-utility does not handle Jewish holidays and moon phases.
+utility does not handle Jewish holidays.
+.Pp
+There is no possibility to properly specify the local position
+needed for solar and lunar calculations.