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) 2009-2021, 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
32package 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   -- Local_Time_Offset --
43   -----------------------
44
45   function Local_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 Local_Time_Offset;
68
69end Ada.Calendar.Time_Zones;
70