@mickaela I will tell you my 20 month olds routine that has been working for us for the past 2 months (knock on wood). Some context to keep in mind - I work from home and we have a nanny that watches him during the week.
6:30 he wakes up and hangs out in his crib fairly quietly for 30 minutes or so until we come into his room. I usually put one of him favorite stuffed toys safe for the crib in the corner and he finds it when he wakes up and it keeps him entertained until 7.
7:30-8:00 Breakfast and then offer him a bottle of milk. Sometime he drinks sometimes he doesn’t.
12:00-12:30 Lunch with milk
1:00-2:30 Nap
3:30 snack with milk
5:00-5:30 Dinner with milk
6:00-6:30 Bath time and while he bathes he snacks on some sort crackers (I think these help with keeping him full through the night)
6:45 Read a couple of books
7:00 - 7:30 Finishes his last bottle and is asleep no later than 7:30.
He will occasionally wake up in the middle of night but we don’t go in unless he is sick. Usually after 2 minutes of whining he falls back asleep.
The key is to let them cry it out. It takes about 3-5 nights of them getting used to the new schedule and then something clicks in their little brain that the parent will not be showing up so they go back to sleep.
Good luck