Since Udemy has sales and such, are there best times to publish your course?
The best time to publish is when you have brought forward the best unique course in your area @KanataCode . Chasing sales programmes on Udemy isn't a marketing strategy. It is not easy to get noticed in a crowded marketplace. Ensure you have a solid marketing strategy in place long before you hit publish to help you get started. Udemy have some great tips to assist you.
Good luck.