When's the right time to ask for a recommendation letter?

So, I’ve been stressing about whether I should ask for a recommendation letter from my professor, and I keep wondering when the best time to do it is. I’ve heard differing opinions—some say ask well in advance, while others suggest closer to the deadline. I want to make sure I give them enough time without it being too early. What has worked for you guys? Any tips on how to approach them without feeling awkward?