Fork me on GitHub

(t/format (tformat/formatter "YYYY") (t/zoned-date-time "2020-12-27T11:00:00Z[Europe/Amsterdam]"))
The above yields "2021" when ran from repl started as clj -J-Duser.language=en -Sdeps '{:deps {tick/tick {:mvn/version "0.4.27-alpha"}}}' -e '(require (quote [tick.alpha.api :as t]) (quote [tick.format :as tformat]))' -r . It yields "2020" (as expected) when using JVM-options -J-Duser.language=en . Any idea what’s going on?

Caro A15:12:49

This relates to the underlying Java DateTimeFormatter, and the fact that Y is week-based year, you might want to use u instead of Y - see