gcc/ada/libgnat/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) 2009-2020, 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 3,  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.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 package body Ada.Calendar.Time_Zones is
  33
  34    --------------------------
  35    -- Implementation Notes --
  36    --------------------------
  37
  38    --  All operations in this package are target and time representation
  39    --  independent, thus only one source file is needed for multiple targets.
  40
  41    ---------------------
  42    -- UTC_Time_Offset --
  43    ---------------------
  44
  45    function UTC_Time_Offset (Date : Time := Clock) return Time_Offset is
  46       Offset_L : constant Long_Integer :=
  47         Time_Zones_Operations.UTC_Time_Offset (Date);
  48       Offset   : Time_Offset;
  49
  50    begin
  51       if Offset_L = Invalid_Time_Zone_Offset then
  52          raise Unknown_Zone_Error;
  53       end if;
  54
  55       --  The offset returned by Time_Zones_Operations.UTC_Time_Offset is in
  56       --  seconds, the returned value needs to be in minutes.
  57
  58       Offset := Time_Offset (Offset_L / 60);
  59
  60       --  Validity checks
  61
  62       if not Offset'Valid then
  63          raise Unknown_Zone_Error;
  64       end if;
  65
  66       return Offset;
  67    end UTC_Time_Offset;
  68
  69 end Ada.Calendar.Time_Zones;