← All modules

strftime for Raku's DateTime — the % patterns everyone knows, with month and day names in six languages.

Version

0.1.5 zef:raku-community-modules

Depends

nothing outside the core

License

Artistic-2.0

Its own test suite

3 files, green

Checked

2026-08-28 against Raku++ 3.20.1 and Rakudo 2026.08

Where it lives

raku.land · source

Install it #

$ rakupp install DateTime::Format

zef install DateTime::Format writes the same store; either installer leaves the module usable by both engines.

What it is for #

Core DateTime prints ISO 8601 and nothing else. The moment a human is going to read the timestamp — a log line, a report header, a filename — you want strftime, the little pattern language that has outlived every framework since C. This module is that, for Raku:

use DateTime::Format;

my $dt = DateTime.new('2026-08-28T14:30:00+02:00');
say strftime('%Y-%m-%d %H:%M', $dt);
say strftime('%A, %B %d', $dt);
say strftime('%a %d %b %Y %T %z', $dt);

2026-08-28 14:30
Friday, August 28
Fri 28 Aug 2026 14:30:00 +0200

The patterns are the classic set: %Y/%m/%d for the date parts, %H/%M/%S (and %T for all three), %A/%a for the weekday spelled out or abbreviated, %B/%b the same for months, %z for the numeric offset, %s for epoch seconds, %% for a literal percent. Anything the pattern does not claim passes through untouched, so slashes, colons and words just work.

Month names in your language #

The names behind %A and %B are pluggable, and the distribution ships them for German, French, Dutch, Portuguese and Bulgarian alongside English. Load a language module and select it:

use DateTime::Format;
use DateTime::Format::Lang::FR;

set-datetime-format-lang('fr');
say strftime('%A %d %B %Y', DateTime.new('2026-08-28T00:00:00Z'));

vendredi 28 août 2026

set-datetime-format-lang switches the default; strftime's :lang named argument does it per call. Your own language is add-datetime-format-month-names('xx', @names) away — the lists are just data.

What about parsing? #

Honesty requires a warning here: the module declares strptime — the inverse, pattern-driven parsing — but in version 0.1.5 it is a stub, and calling it dies with Stub code executed on any engine. The bundled DateTime::Format::RFC2822 class's from-string routes into the same stub, so it cannot parse either. For parsing, stay with DateTime.new on ISO strings or write a grammar; this page documents what runs, and pattern-driven parsing is not yet part of that. Formatting — every example above — is complete.

Where the two engines differ #

Nothing on this page. Every pattern shown, the language switching, and even the strptime stub's failure mode behave identically under Raku++ and Rakudo.

What was run to put this page here #

1. Parse — every file of the distribution is parsed by Raku++ itself.
2. Install — rakupp install DateTime::Format; it depends on nothing outside the core.
3. Test — the distribution's own suite: 3 files, green.
4. Run — every example on this page, twice under each engine, as the site is built.

Thirteen distributions depend on it. Note that the example outputs above are stable because the input DateTime carries its own offset — format a DateTime.now and your %z will be your machine's, which is the correct kind of instability.