#iso8601 #weeknumber
https://tessarinseve.pythonanywhere.com/isoweek

@tykling but #ISO8601 has so many nice things that aren't in #RFC3339 /o\
https://ijmacd.github.io/rfc3339-iso8601/

@nerdsticker #TIL about #Iso8601

Happy (ISO week date) New Year!
https://chrisphan.com/posts/2025-12-29_happy_new_year.html
#iso8601 #isoweekdate #2026

TIL about date -I which gives you ISO8601 dates without faffing around with the percent sign formatting.

Plus it has a “precision” modifier which can give you the rest: date -Iseconds → 2025-12-29T10:18:20+00:00; date -Ihours → 2025-12-29T10+00:00; etc. (You can truncate the hours to h and it still works.)

Time to update about a million of my shell scripts!

#TIL #ISO8601

@RichiH OMG, the #ISO8601 Ultras! Didn't know that I NEED those! 😍
Too bad I'm 1500km further south.

I have a few stickers with me at #39c3 btw. Mainly #grafana , some #ISO8601

Find me if you want stickers

CC @c3stoc

#ISO8601 #commonLisp #programming: https://screwlisp.small-web.org/kitten/actual-kitten-experience/#but-first-a-common-lisp-FIPA-SL-modified-ISO8601-date-timestamper

(let ((* (multiple-value-list
(decode-universal-time
(get-universal-time) 0))))
(format nil "~@{~?~}"
"~10,4,'0r" (list (sixth *))
"~10,2,'0r" (list (fifth *))
"~10,2,'0r" (list (fourth *))
"~a" (list #\T)
"~10,2,'0r" (list (third *))
"~10,2,'0r" (list (second *))
"~10,2,'0r" (list (first *))
"~10,3,'0r"
(list (rem (get-internal-real-time)
internal-time-units-per-second))
"~a" (list #\Z)))

My Actual #smallweb kitten experience.
https://screwlisp.small-web.org/kitten/actual-kitten-experience/

What I discovered is that #webdev -ing an article "properly" which is to say using all the features your framework provides (i.e. https://kitten.small-web.org/ ) absorbs an absolute ton of extra work. Comparable to being formal in mathematics. I am interested in how that extra work exposes my own articles to me better later.

I also propose FIPA SL's extension to #ISO8601 as a general time format in #commonLisp . cc @aral

I use the ISO week-date calendar for my personal journal and notes. Today begins the last week of 2025 under that system. It's a good opportunity to reflect on what has happened these 52 weeks and what I want my life to look like going forward. #ISO8601 #2025 #personalThoughts

The first ISO8601ultras sticker are now available in the stickerbox at @uwuspace Zurich

#stickerart #stickers #iso8601ultras #ISO8601

@FlohEinstein speaking of which...

I've got 50 of those so I won't distribute them too widely, but anyone who finds me can have some

#39c3 #sticker #stickers #iso8601

@dgar

I tried to be there and fully aware, on the 12th.

Sadly, I could not figure out, for the life of mine, what the name of the 31st month was, and so the date just passed, without me noticing anything in peculiar.

#ISO8601 #ISO8601ultras

@cstross Reminds me of the hoops I have to jump through to get #iso8601 dates in my #Debian apps via the `LC_TIME` environment variable and a bespoke `en_SE` “English - Sweden” custom locale. https://blog.carsoncheng.ca/2021/03/use-iso-8601-dates-in-pcmanfm-on-debian.html . This was the “easiest” solution I found in 2022 after exploring options to get #Firefox, #Thunderbird, and other apps to display YYYY-mm-dd HH:MM:SS style time stamps.

In #macOS, I think you just modify `System Preferences > Language & Region > Advanced > Dates`.

@FlohEinstein Nice, but nowadays it should be RFC 9557!

https://datatracker.ietf.org/doc/html/rfc9557

Plain RFC 3339 / ISO 8601 is lossy and thus insufficient.

#iso8601

Which version best conveys the message "ISO 8601. Every over date/time format is inferior"?
Based on different versions of the original logo I made multiple attempts. One of them will become a sticker. White on red, Blue on White or White on Blue?

EDIT: Since there was no consensus and some even tried to get me to different teams (RFC 3339, RFC 9557) I just sent an order for every version.

#iso8601 #iso8601ultras #stickerart #39c3 #infosec #stickers #bestpractice

@alech Hab vorhin was mit #ISO8601 getaggt, da wurde mir #iso8601ultras vorgeschlagen... Oh Mann, war das Hashtag nötig? Ich wollte mal für ein paar Tage keine neuen Sticker-Ideen in meinem Kopf ausbrüten... OK, erst mal Frühstücken, dann Inkscape öffnen

I just realized that the International Organization for Standardization ISO uses a picture from Switzerland to illustrate their popular standards page about ISO8601.
But do you know where it was taken?

https://www.iso.org/iso-8601-date-and-time-format.html

#iso8601 #switzerland #schweiz #geoguess #architecture

π Happy ordinal pi day! (314th day of the year)

No, it should not be the US-centric March 14th, which most of the world writes as 14/3 or 14-3.

Science and mathematics are international, without borders, not specific to any one country or culture. As scientists and mathematicians we should seek international-based celebrations that bring us all together around the globe rather than country-specific dates.

The ordinal date (ISO 8601) is the only way to have an international nth day of the year: https://en.wikipedia.org/wiki/Ordinal_date

Similarly:

* 88th day: worldwide Piano Day: https://en.wikipedia.org/wiki/Piano_Day (blogged https://tantek.com/2024/088/t1/world-piano-day-ordinal-date-iso-8601)
* 256the day: 8-bit day or https://en.wikipedia.org/wiki/Programmer%27s_Day (blogged https://tantek.com/2025/257/t1/happy-8bitday-255-bytes-max)

I suspect there are other such annual worldwide holidays that are pinned to the ordinal date rather than a Gregorian or other non-decimal calendar. Let me know if you have a favorite that you celebrate!

🥧 I haven't made a pie (or picked one up) yet — will have go pick up a slice during a break in this evening’s #w3cTPAC meetings (which are in Japan where it’s already the day after pi day).

Previously:
* https://tantek.com/2022/314/t1/happy-ordinal-pi-day

#piDay #actualPiDay #ordinalDate #ISO8601 #ISOdate

Y'all owe a huge amount of gratitude to @jamie for playing along with my evil schemes and persevering through a whole year for this seemingly trivial merge request: https://gitlab.gnome.org/GNOME/gsettings-desktop-schemas/-/merge_requests/93

…to allow #GNOMECalendar, #GNOMEShell, @EvolutionGnome and other apps to finally let you use a custom "first day of the week" independently from your language or geographic location!

See the plan here: https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/160#note_1872970 — Who will first implement it in GNOME Calendar? MRs welcome!

#GNOME #ISO8601