1 /* Demonstrate conversions between a local time and utc
2 * Output:
3 *
4 * UTC <--> New York while DST is NOT active (5 hours)
5 * 2001-Dec-31 19:00:00 in New York is 2002-Jan-01 00:00:00 UTC time
6 * 2002-Jan-01 00:00:00 UTC is 2001-Dec-31 19:00:00 New York time
7 *
8 * UTC <--> New York while DST is active (4 hours)
9 * 2002-May-31 20:00:00 in New York is 2002-Jun-01 00:00:00 UTC time
10 * 2002-Jun-01 00:00:00 UTC is 2002-May-31 20:00:00 New York time
11 *
12 * UTC <--> Arizona (7 hours)
13 * 2002-May-31 17:00:00 in Arizona is 2002-Jun-01 00:00:00 UTC time
14 */
15
16 #include "boost/date_time/posix_time/posix_time.hpp"
17 #include "boost/date_time/local_time_adjustor.hpp"
18 #include "boost/date_time/c_local_time_adjustor.hpp"
19 #include <iostream>
20
21 int
main()22 main()
23 {
24 using namespace boost::posix_time;
25 using namespace boost::gregorian;
26
27 //This local adjustor depends on the machine TZ settings-- highly dangerous!
28 typedef boost::date_time::c_local_adjustor<ptime> local_adj;
29 ptime t10(date(2002,Jan,1), hours(7));
30 ptime t11 = local_adj::utc_to_local(t10);
31 std::cout << "UTC <--> Zone base on TZ setting" << std::endl;
32 std::cout << to_simple_string(t11) << " in your TZ is "
33 << to_simple_string(t10) << " UTC time "
34 << std::endl;
35 time_duration td = t11 - t10;
36 std::cout << "A difference of: "
37 << to_simple_string(td) << std::endl;
38
39
40 //eastern timezone is utc-5
41 typedef boost::date_time::local_adjustor<ptime, -5, us_dst> us_eastern;
42
43 ptime t1(date(2001,Dec,31), hours(19)); //5 hours b/f midnight NY time
44
45 std::cout << "\nUTC <--> New York while DST is NOT active (5 hours)"
46 << std::endl;
47 ptime t2 = us_eastern::local_to_utc(t1);
48 std::cout << to_simple_string(t1) << " in New York is "
49 << to_simple_string(t2) << " UTC time "
50 << std::endl;
51
52 ptime t3 = us_eastern::utc_to_local(t2);//back should be the same
53 std::cout << to_simple_string(t2) << " UTC is "
54 << to_simple_string(t3) << " New York time "
55 << "\n\n";
56
57 ptime t4(date(2002,May,31), hours(20)); //4 hours b/f midnight NY time
58 std::cout << "UTC <--> New York while DST is active (4 hours)" << std::endl;
59 ptime t5 = us_eastern::local_to_utc(t4);
60 std::cout << to_simple_string(t4) << " in New York is "
61 << to_simple_string(t5) << " UTC time "
62 << std::endl;
63
64 ptime t6 = us_eastern::utc_to_local(t5);//back should be the same
65 std::cout << to_simple_string(t5) << " UTC is "
66 << to_simple_string(t6) << " New York time "
67 << "\n" << std::endl;
68
69
70 //Arizona timezone is utc-7 with no dst
71 typedef boost::date_time::local_adjustor<ptime, -7, no_dst> us_arizona;
72
73 ptime t7(date(2002,May,31), hours(17));
74 std::cout << "UTC <--> Arizona (7 hours)" << std::endl;
75 ptime t8 = us_arizona::local_to_utc(t7);
76 std::cout << to_simple_string(t7) << " in Arizona is "
77 << to_simple_string(t8) << " UTC time "
78 << std::endl;
79
80 return 0;
81 }
82
83
84 /* Copyright 2001-2004: CrystalClear Software, Inc
85 * http://www.crystalclearsoftware.com
86 *
87 * Subject to the Boost Software License, Version 1.0.
88 * (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
89 */
90
91