Package: Util.Calendar

Dependencies

with Ada.Calendar;

Description

Copyright © 2001, 2002 by Thomas Wolf.
This piece of software is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This software is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License with this distribution, see file "GPL.txt". If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
As a special exception from the GPL, if other files instantiate generics from this unit, or you link this unit with other files to produce an executable, this unit does not by itself cause the resulting executable to be covered by the GPL. This exception does not however invalidate any other reasons why the executable file might be covered by the GPL.

Version: 1.1

Author:
Thomas Wolf (TW) <twolf AT acm DOT org>
Purpose:
Root package of the calendar subsystem. Provides a day-of-week calculation for Gregorian dates.
Literature:

See Christian Zeller; Kalender-Formeln, Acta Mathematica, vol. 9, pp. 131-136; Nov. 1886. (Yes, that's not a typo, it really appeared in eighteen-eightysix. In fact, that paper is an expanded version of an earlier one from 1883!)

See also J.R. Stockton's page on Zeller's congruence.

Header

package Util.Calendar is

 
pragma Elaborate_Body;
Can't be pure, because Ada.Calendar isn't pure.

Known child units

Util.Calendar.IO(package)
Util.Calendar.UTC(package)

Type Summary

Hours_Type derived from Natural
Minutes_Type derived from Natural
Seconds_Type derived from Natural
Weekday

Other Items:

type Weekday is (Mon, Tue, Wed, Thu, Fri, Sat, Sun);
function Day_Of_Week
  (Year  : in Ada.Calendar.Year_Number;
   Month : in Ada.Calendar.Month_Number;
   Day   : in Ada.Calendar.Day_Number)
  return Weekday;
function Day_Of_Week
  (Date : in Ada.Calendar.Time)
  return Weekday;
Returns the day of the week. Works for all Gregorian dates. Provided here because it makes available this functionality for standard Ada.Calendar times without dragging in all the extended calendar support. 
type Hours_Type   is new Natural range 0 .. 23;
type Minutes_Type is new Natural range 0 .. 59;
type Seconds_Type is new Natural range 0 .. 59;
procedure Split
  (Secs : in     Ada.Calendar.Day_Duration;
   Hrs  :    out Hours_Type;
   Min  :    out Minutes_Type;
   Sec  :    out Seconds_Type;
   Frac :    out Ada.Calendar.Day_Duration);
Split a number of seconds Secs into hours, minutes, seconds, and a sub-second fraction. 
end Util.Calendar;
Generated on 2002-12-01 at 14:23:16 by AdaBrowse 3.2 using configuration files util.cfg, common.cfg.