Update: It seems like this is not restricted to Java, but this issue is happening across many languages due to a change in how date formatting is handled in Unicode. I'll look for a fix and post a code analysis.
I have managed to reproduce the issue on macOS, on a fresh install of Minecraft and Java 20.
This is definitely a modded environment, as this issue is caused by an mod failing to inject into the vanilla game code.
ims212
Update: It seems like this is not restricted to Java, but this issue is happening across many languages due to a change in how date formatting is handled in Unicode. I'll look for a fix and post a code analysis.