day_of_year()

uint32 xtd::date_time::day_of_year ( ) const

noexcept

Gets the day of the year represented by this instance.

Returns

The day of the year, expressed as a value between 1 and 366.

Examples

The following example displays the day of the year of December 31 for the years 2010-2020 in the Gregorian calendar. Note that the example shows that December 31 is the 366th day of the year in leap years.

#include <xtd/console>
#include <xtd/date_time>
#include <xtd/startup>
 
using namespace xtd;
 
class program {
public:
  static auto main() {
    auto dec31 = date_time {2010, 12, 31};
    for (auto ctr = 0u; ctr <= 10u; ctr++) {
      auto date_to_display = dec31.add_years(ctr);
      console::write_line("{0:d}: day {1} of {2} {3}", date_to_display, date_to_display.day_of_year(), date_to_display.year(), date_time::is_leap_year(date_to_display.year()) ? "(Leap Year)" : "");
    }
  }
};
 
startup_(program::main);
 
// This code produces the following output :
//
// 12/31/2010: day 365 of 2010
// 12/31/2011: day 365 of 2011
// 12/31/2012: day 366 of 2012 (Leap Year)
// 12/31/2013: day 365 of 2013
// 12/31/2014: day 365 of 2014
// 12/31/2015: day 365 of 2015
// 12/31/2016: day 366 of 2016 (Leap Year)
// 12/31/2017: day 365 of 2017
// 12/31/2018: day 365 of 2018
// 12/31/2019: day 365 of 2019
// 12/31/2020: day 366 of 2020 (Leap Year)

Remarks

The xtd::date_time::day_of_year property takes leap years into account when it calculates the day of the year. The property value always reflects the day of the year in the Gregorian calendar, regardless of the current culture's current calendar.