islamic+This is an Islamic calendar in the style of +date.h. +Everthing is the same here as for +date.h, +except that the calendrical arithmetic implements a proleptic +Tabular Islamic calendar. +
+ +
+The islamic calendar can interoperate with
+date.h and tz.h just by
+paying attention to the namespace. For example to convert the civil
+date 2016_y/jul/4 to an islamic date, just do:
+
+#include "islamic.h"
+#include <iostream>
+
+int
+main()
+{
+ using namespace date::literals;
+ std::cout << islamic::year_month_day{2016_y/jul/4} << '\n';
+}
++This outputs: +
+ ++ ++1437-09-28 +
+And here is the reverse conversion: +
+ +
+#include "islamic.h"
+#include <iostream>
+
+int
+main()
+{
+ using namespace islamic::literals;
+ std::cout << date::year_month_day{1437_y/9/28} << '\n';
+}
++Which outputs: +
+ ++ ++2016-07-04 +
+You can even convert directly to the ISO-week-based calendar: +
+ +
+#include "islamic.h"
+#include "iso_week.h"
+#include <iostream>
+
+int
+main()
+{
+ using namespace islamic::literals;
+ std::cout << iso_week::year_weeknum_weekday{2016_y/jun/13} << '\n';
+}
++Which outputs: +
+ ++ ++2016-W27-Mon +
+ +
+You can find the current local islamic date and time with: +
+ +
+#include "islamic.h"
+#include "tz.h"
+#include <iostream>
+
+int
+main()
+{
+ auto zt = date::make_zoned(date::current_zone(), std::chrono::system_clock::now());
+ auto ld = date::floor<date::days>(zt.get_local_time());
+ julian::year_month_day ymd{ld};
+ auto time = date::make_time(zt.get_local_time() - ld);
+ std::cout << ymd << ' ' << time << '\n';
+}
++Example output: +
+ ++ ++1437-09-28 16:24:56.578240 +
+This calendar assumes that the Islamic day starts at midnight, like the civil
+calendar. This is because the only thing that is customized to the Islamic
+calendar is the calendar itself (days precision time keeping). For time-keeping
+finer than days, the <chrono> library is still in use. The
+Islamic calendar simply converts to and from sys_days (a
+days-precision std::chrono::time_point) like every other calendar.
+