kind()

date_time_kind xtd::date_time::kind ( ) const

noexcept

Gets a value that indicates whether the time represented by this instance is based on local time, Coordinated Universal Time (UTC), or neither.

Returns

One of the enumeration values that indicates what the current time represents. The default is xtd::date_time_kind::unspecified.

Examples

The following example uses the xtd::date_time::specify_kind method to demonstrate how the xtd::date_time::kind property influences the xtd::date_time::to_local_time and xtd::date_time::to_universal_time conversion methods.

#include <xtd/console>
#include <xtd/date_time>
#include <xtd/startup>
 
using namespace xtd;
 
class program {
public:
  static auto main() {
    // Get the date and time for the current moment, adjusted
    // to the local time zone.
    
    auto save_now = date_time::now();
    
    // Get the date and time for the current moment expressed
    // as coordinated universal time (UTC).
    
    auto save_utc_now = date_time::utc_now();
    auto my_dt = date_time {};
    
    // display the value and kind property of the current moment
    // expressed as UTC and local time.
    
    display_now("utc_now: ...........", save_utc_now);
    display_now("now: ...............", save_now);
    console::write_line();
    
    // Change the kind property of the current moment to
    // date_time_kind::utc and display the result.
    
    my_dt = date_time::specify_kind(save_now, date_time_kind::utc);
    display("utc: ...............", my_dt);
    
    // Change the kind property of the current moment to
    // date_time_kind::local and display the result.
    
    my_dt = date_time::specify_kind(save_now, date_time_kind::local);
    display("local: .............", my_dt);
    
    // Change the kind property of the current moment to
    // date_time_kind::unspecified and display the result.
    
    my_dt = date_time::specify_kind(save_now, date_time_kind::unspecified);
    display("unspecified: .......", my_dt);
  }
  
  // display the value and kind() property of a date_time structure, the
  // date_time structure converted to local time, and the date_time
  // structure converted to universal time.
  
  static void display(const string& title, const date_time& input_dt) {
    auto disp_dt = input_dt;
    auto dt_string = string::empty_string;
    
    // display the original date_time.
    
    dt_string = disp_dt.to_string("u");
    console::write_line("{0} {1}, kind = {2}", title, dt_string, disp_dt.kind());
    
    // Convert input_dt to local time and display the result.
    // If input_dt.kind() is date_time_kind.Utc, the conversion is performed.
    // If input_dt.kind() is date_time_kind::local, the conversion is not performed.
    // If input_dt.kind() is date_time_kind::unspecified, the conversion is
    // performed as if input_dt was universal time.
    
    disp_dt = input_dt.to_local_time();
    dt_string = disp_dt.to_string("u");
    console::write_line("  to_local_time:     {0}, kind = {1}", dt_string, disp_dt.kind());
    
    // Convert input_dt to universal time and display the result.
    // If input_dt.kind() is date_time_kind.Utc, the conversion is not performed.
    // If input_dt.kind() is date_time_kind::local, the conversion is performed.
    // If input_dt.kind() is date_time_kind::unspecified, the conversion is
    // performed as if input_dt was local time.
    
    disp_dt = input_dt.to_universal_time();
    dt_string = disp_dt.to_string("u");
    console::write_line("  to_universal_time: {0}, kind = {1}", dt_string, disp_dt.kind());
    console::write_line();
  }
  
  // display the value and kind property for date_time::now() and date_time::utc_now().
  
  static void display_now(const string& title, const date_time& input_dt) {
    auto dt_string = input_dt.to_string("u");
    console::write_line("{0} {1}, kind = {2}", title, dt_string, input_dt.kind());
  }
};
 
startup_(program::main);
 
// This code can produce the following output :
//
// utc_now: ........... 2021-12-31 17:08:41, Kind = utc
// now: ............... 2021-12-31 18:08:41, Kind = local
//
// utc: ............... 2021-12-31 17:08:41, Kind = utc
//   to_local_time:     2021-12-31 18:08:41, Kind = local
//   to_universal_time: 2021-12-31 17:08:41, Kind = utc
//
// local: ............. 2021-12-31 18:08:41, Kind = local
//   to_local_time:     2021-12-31 18:08:41, Kind = local
//   to_universal_time: 2021-12-31 17:08:41, Kind = utc
//
// unspecified: ....... 2021-12-31 18:08:41, Kind = unspecified
//   to_local_time:     2021-12-31 19:08:41, Kind = local
//   to_universal_time: 2021-12-31 17:08:41, Kind = utc

Remarks

You can explicitly set the xtd::date_time::xtd::date_time::kind property of a new xtd::date_time value to a particular xtd::date_time_kind value by calling the xtd::date_time::specify_kind method.

The xtd::date_time::kind property allows a xtd::date_time value to clearly reflect either Coordinated Universal Time (UTC) or the local time. In contrast, the xtd::date_time_offset structure can unambiguously reflect any time in any time zone as a single point in time.

Examples

date_time_specify_kind.cpp.