Thanks for the review.

I committed the changes for localization. I went with {{ msg('datetime-formatted', [msg('start-date-label'), contest.start_date]) }} where datetime-formatted is $1 $2 UTC and $1 is msg('start-date-label') or msg('end-date-label'). Well both approach works here, yours and mine. IDK why I went with my but when testing things I went with this one and that's what I committed. If you want them in {{ msg( msg('datetime-formatted', [contest.start_date]) ) }}, I will be happy to do the same.

For the languages:
I was familiar with some languages like Punjabi, Nepali, and English. For other languages I used the help of google translator for the languages that has field times-are-utc for referencing that the translations are in proper style.

Sorry, I totally didn't mean to add two msg() calls in that example! Sorry for the confusion.

It's best not to include messages as parameters to other messages (known as patchwork messages), so I'd recommend just adding this new message on its own.

For the other languages, that's great that you did the research etc., but there's no need to add them in as they'll be done by TranslateWiki.net. The translators ask us to leave them out; see https://www.mediawiki.org/wiki/Help:System_message#Changing_existing_messages

Thank you for the review and guidance!

I've updated the implementation to use start-date-formatted and end-date-formatted message as discussed, ensuring that each message is self-contained and avoids patchwork messaging. The other language files remain unchanged, in line with the workflow for Translatewiki.net

On a related note, I wasn't aware that translations are exclusively handled by TranslateWiki.net until this discussion. It might be helpful if this information is documented in the CONTRIBUTING.md file or somewhere similar for contributors who may not know. If it’s already documented and I missed it, I apologize!

Please let me know if there are any further changes needed.

Thanks!