I think it’s the abbreviation for the Polish word for week which is “tydzień”.
This label has been changed to “1w” three days ago in the translation repository, so one of the next patches should change it to that.
https://translate.codeberg.org/translate/kbin/kbin/en/?checksum=230b39cf2d496441
EDIT: Link that goes to the history directly: https://translate.codeberg.org/translate/kbin/kbin/en/?checksum=230b39cf2d496441#history
Ernest is from Poland. In Polish, the word for week is “tydzień,” which starts with the letter “t.”
According to the timestamps you bet me to it :-) When I hit reply I swear your comment wasn’t there!?
Comments don’t propagate extremely efficiently. So viewing a post on one instance may not show the same comments when viewed from another instance. Eventually they catch up, but when discussing small timeframes, it’s possible you’ll miss some.
One forTnight
One twoweeks
