// Written in the D programming language /++    $(SCRIPT inhibitQuickIndex = 1;)     Phobos provides the following functionality for time:     $(DIVC quickindex,    $(BOOKTABLE ,    $(TR $(TH Functionality) $(TH Symbols)    )    $(TR        $(TD Points in Time)        $(TD            $(REF_ALTTEXT Clock, Clock, std, datetime, systime)$(NBSP)            $(REF_ALTTEXT Date, Date, std, datetime, date)$(NBSP)            $(REF_ALTTEXT TimeOfDay, TimeOfDay, std, datetime, date)$(NBSP)            $(REF_ALTTEXT DateTime, DateTime, std, datetime, date)$(NBSP)            $(REF_ALTTEXT SysTime, SysTime, std, datetime, systime)$(NBSP)        )    )    $(TR        $(TD $(MREF_ALTTEXT Timezones, std, datetime, timezone))        $(TD            $(REF_ALTTEXT TimeZone, TimeZone, std, datetime, timezone)$(NBSP)            $(REF_ALTTEXT UTC, UTC, std, datetime, timezone)$(NBSP)            $(REF_ALTTEXT LocalTime, LocalTime, std, datetime, timezone)$(NBSP)            $(REF_ALTTEXT PosixTimeZone, PosixTimeZone, std, datetime, timezone)$(NBSP)            $(REF_ALTTEXT WindowsTimeZone, WindowsTimeZone, std, datetime, timezone)$(NBSP)            $(REF_ALTTEXT SimpleTimeZone, SimpleTimeZone, std, datetime, timezone)$(NBSP)        )    )    $(TR        $(TD Intervals and Ranges of Time)        $(TD            $(REF_ALTTEXT Interval, Interval, std, datetime, interval)$(NBSP)            $(REF_ALTTEXT PosInfInterval, PosInfInterval, std, datetime, interval)$(NBSP)            $(REF_ALTTEXT NegInfInterval, NegInfInterval, std, datetime, interval)$(NBSP)        )    )    $(TR        $(TD $(MREF_ALTTEXT Durations of Time, core, time))        $(TD            $(REF_ALTTEXT Duration, Duration, core, time)$(NBSP)            $(REF_ALTTEXT weeks, weeks, core, time)$(NBSP)            $(REF_ALTTEXT days, days, core, time)$(NBSP)            $(REF_ALTTEXT hours, hours, core, time)$(NBSP)            $(REF_ALTTEXT minutes, minutes, core, time)$(NBSP)            $(REF_ALTTEXT seconds, seconds, core, time)$(NBSP)            $(REF_ALTTEXT msecs, msecs, core, time)$(NBSP)            $(REF_ALTTEXT usecs, usecs, core, time)$(NBSP)            $(REF_ALTTEXT hnsecs, hnsecs, core, time)$(NBSP)            $(REF_ALTTEXT nsecs, nsecs, core, time)$(NBSP)        )    )    $(TR        $(TD Time Measurement and Benchmarking)        $(TD            $(REF_ALTTEXT MonoTime, MonoTime, core, time)$(NBSP)            $(REF_ALTTEXT StopWatch, StopWatch, std, datetime, stopwatch)$(NBSP)            $(REF_ALTTEXT benchmark, benchmark, std, datetime, stopwatch)$(NBSP)        )    )    ))     This functionality is separated into the following modules:     $(UL        $(LI $(MREF std, datetime, date) for points in time without timezones.)        $(LI $(MREF std, datetime, timezone) for classes which represent timezones.)        $(LI $(MREF std, datetime, systime) for a point in time with a timezone.)        $(LI $(MREF std, datetime, interval) for types which represent series of points in time.)        $(LI $(MREF std, datetime, stopwatch) for measuring time.)    )     See_Also:        $(MREF core, time)$(BR)        $(DDLINK intro-to-datetime, Introduction to std.datetime,                 Introduction to std&#46;datetime)<br>        $(HTTP en.wikipedia.org/wiki/ISO_8601, ISO 8601)<br>        $(HTTP en.wikipedia.org/wiki/Tz_database,              Wikipedia entry on TZ Database)<br>        $(HTTP en.wikipedia.org/wiki/List_of_tz_database_time_zones,              List of Time Zones)<br>     License:   $(HTTP www.boost.org/LICENSE_1_0.txt, Boost License 1.0).    Authors:   $(HTTP jmdavisprog.com, Jonathan M Davis) and Kato Shoichi    Source:    $(PHOBOSSRC std/datetime/package.d)+/module std.datetime; /// Get the current time from the system clock.@safe unittest{    import std.datetime.systime : SysTime, Clock;     SysTime currentTime = Clock.currTime();} /**Construct a specific point in time without timezone informationand get its ISO string. */@safe unittest{    import std.datetime.date : DateTime;     auto dt = DateTime(2018, 1, 1, 12, 30, 10);    assert(dt.toISOString() == "20180101T123010");    assert(dt.toISOExtString() == "2018-01-01T12:30:10");} /**Construct a specific point in time in the UTC timezone andadd two days. */@safe unittest{    import std.datetime.systime : SysTime;    import std.datetime.timezone : UTC;    import core.time : days;     auto st = SysTime(DateTime(2018, 1, 1, 12, 30, 10), UTC());    assert(st.toISOExtString() == "2018-01-01T12:30:10Z");    st += 2.days;    assert(st.toISOExtString() == "2018-01-03T12:30:10Z");} public import core.time;public import std.datetime.date;public import std.datetime.interval;public import std.datetime.systime;public import std.datetime.timezone; import core.exception : AssertError;import std.functional : unaryFun;import std.traits;import std.typecons : Flag, Yes, No;  // Verify module example.@safe unittest{    auto currentTime = Clock.currTime();    auto timeString = currentTime.toISOExtString();    auto restoredTime = SysTime.fromISOExtString(timeString);} // Verify Examples for core.time.Duration which couldn't be in core.time.@safe unittest{    assert(std.datetime.Date(2010, 9, 7) + dur!"days"(5) ==           std.datetime.Date(2010, 9, 12));     assert(std.datetime.Date(2010, 9, 7) - std.datetime.Date(2010, 10, 3) ==           dur!"days"(-26));} @safe unittest{    import std.traits : hasUnsharedAliasing;    /* https://issues.dlang.org/show_bug.cgi?id=6642 */    static assert(!hasUnsharedAliasing!Date);    static assert(!hasUnsharedAliasing!TimeOfDay);    static assert(!hasUnsharedAliasing!DateTime);    static assert(!hasUnsharedAliasing!SysTime);}