Ignore it. That date is a suggestion, not a command. Mustard doesn’t care about time. It lives in a permanent state of “still good.”
I have a bottle of French’s from 2026 in my pantry right now. It’s laughing at the calendar. It’s fine. It will be fine when my grandchildren find it.
Just give it a sniff and a stir if it looks weird. If it smells like vinegar and sunshine, you’re golden. If it smells like regret, toss it. But that won’t happen.