when’s the best time to shop?

i never shop at ulta, my first and only purchase was cécred hair drops which earned me $3 in rewards back in june but now i’m thinking of buying the complete cécred max sizes set + the gel and mousse— i have a 20% off coupon on the app which is cool but i wanted to know if there were any other sales coming up or better deals before i make such a big purchase lol