auto today()
{
    import std.datetime;
    auto d = cast(DateTime) Clock.currTime();
    import std.format: format;
    return format("%04d/%02d/%02d", d.year, d.month, d.day);
}

void main()
{
    import std.stdio;
    today.writeln;
}

On Saturday, 4 May 2019 at 03:15:59 UTC, Hello wrote:
> auto today()
> {
>     import std.datetime;
>     auto d = cast(DateTime) Clock.currTime();
>     import std.format: format;
>     return format("%04d/%02d/%02d", d.year, d.month, d.day);
> }
>
> void main()
> {
>     import std.stdio;
>     today.writeln;
> }

The cast is unnecessary, and there is writefln:

void main()
{
    import std.datetime, std.stdio;
    auto d = Clock.currTime();
    writefln("%04d/%02d/%02d", d.year, d.month, d.day);
}

https://run.dlang.io/is/wT6Cn7

On Sat, 2019-05-04 at 08:06 +0000, Bastiaan Veelo via Digitalmars-d wrote:
> […]
> 
> void main()
> {
>      import std.datetime, std.stdio;
>      auto d = Clock.currTime();
>      writefln("%04d/%02d/%02d", d.year, d.month, d.day);
> }

"%04d-%02d-%02d" for ISO8601 compliance.

-- 
Russel.
===========================================
Dr Russel Winder      t: +44 20 7585 2200
41 Buckmaster Road    m: +44 7770 465 077
London SW11 1EN, UK   w: www.russel.org.uk

On Saturday, May 4, 2019 2:06:59 AM MDT Bastiaan Veelo via Digitalmars-d wrote:
> On Saturday, 4 May 2019 at 03:15:59 UTC, Hello wrote:
> > auto today()
> > {
> >
> >     import std.datetime;
> >     auto d = cast(DateTime) Clock.currTime();
> >     import std.format: format;
> >     return format("%04d/%02d/%02d", d.year, d.month, d.day);
> >
> > }
> >
> > void main()
> > {
> >
> >     import std.stdio;
> >     today.writeln;
> >
> > }
>
> The cast is unnecessary, and there is writefln:
>
> void main()
> {
>      import std.datetime, std.stdio;
>      auto d = Clock.currTime();
>      writefln("%04d/%02d/%02d", d.year, d.month, d.day);
> }
>
> https://run.dlang.io/is/wT6Cn7

The cast isn't necessary, but it's more efficient. Internally, it basically doing the equivalent of casting to DateTime every time you ask for the pieces of the date/time such as the year or hour. So, whether is casting is better or not depends on whether you want shorter code or faster code.

- Jonathan M Davis

On Saturday, May 4, 2019 5:17:57 AM MDT Russel Winder via Digitalmars-d wrote:
> On Sat, 2019-05-04 at 08:06 +0000, Bastiaan Veelo via Digitalmars-d wrote:
> > […]
> >
> > void main()
> > {
> >
> >      import std.datetime, std.stdio;
> >      auto d = Clock.currTime();
> >      writefln("%04d/%02d/%02d", d.year, d.month, d.day);
> >
> > }
>
> "%04d-%02d-%02d" for ISO8601 compliance.

If that's what you want, then just cast to Date and call toISOExtString() on
it.

- Jonathan M Davis