Hello
Sorry for the long delay, life got in the way of doing much work on the bot.

First of all, thanks for submitting a PR, we really appreciate contributions to our projects 🙂.
Unfortunately, there's a couple of problems with this PR that mean we can't merge it.

1. The fix you first copied turned out to not actually work as intended. As seen in Set date parameter for greyline instead of nonce #318, it caused wacky caching issues for anyone looking at the message a couple of hours after it was posted.
2. Your new fix imports datetime to get the current minute, despite discord IDs being timestamps with additional data that guarantees uniqueness (the first version of the fix would extract the time from the ID of the received message, ctx.message.id). At one minute of delay, this simply is bruteforcing of the cache, and using a guaranteed unique value (like the ID) would make more sense.
3. That new fix still does not solve the bug observed in Set date parameter for greyline instead of nonce #318.
4. We have not yet found a fix that actually gets rid of the issue (except for ?greyline since the server accepts a date parameter and return an image according to it, PR Fixed ?greyline caching (set date url param) #335).
5. The issue affects other commands.

Normally I'd just post a review with the elements to change, but since this will require an investigation on our part before a fix can be implemented, I am closing this PR.