Overnight oats typically need to be prepared at least 3 hours in advance to allow for sufficient soaking time. But the ideal timeframe is to make the oats the night before, to let them soak overnight, which gives the oats ample time to soften and absorb the flavors of the other ingredients. This longer soaking period also ensures a creamy and delicious texture! Prepping overnight oats the night before or even a couple of nights in advance is a convenient way to have a ready-to-eat breakfast waiting for you in the morning too!