gcc/ada/a-catizo.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --              A D A . C A L E N D A R . T I M E _ Z O N E S               --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --            Copyright (C) 2006, Free Software Foundation, Inc.            --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, USA.                                                      --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 package body Ada.Calendar.Time_Zones is
  35
  36    --------------------------
  37    -- Implementation Notes --
  38    --------------------------
  39
  40    --  All operations in this package are target and time representation
  41    --  independent, thus only one source file is needed for multiple targets.
  42
  43    ---------------------
  44    -- UTC_Time_Offset --
  45    ---------------------
  46
  47    function UTC_Time_Offset (Date : Time := Clock) return Time_Offset is
  48       Offset_L : constant Long_Integer :=
  49                    Time_Zones_Operations.UTC_Time_Offset (Date);
  50       Offset   : Time_Offset;
  51
  52    begin
  53       if Offset_L = Invalid_Time_Zone_Offset then
  54          raise Unknown_Zone_Error;
  55       end if;
  56
  57       --  The offset returned by Time_Zones_Operations.UTC_Time_Offset is in
  58       --  seconds, the returned value needs to be in minutes.
  59
  60       Offset := Time_Offset (Offset_L / 60);
  61
  62       --  Validity checks
  63
  64       if not Offset'Valid then
  65          raise Unknown_Zone_Error;
  66       end if;
  67
  68       return Offset;
  69    end UTC_Time_Offset;
  70
  71 end Ada.Calendar.Time_Zones;