When my ex and I were together we shared childcare, both changed, fed, bathed, put to bed, rocked when crying, stayed up all night when they were sick etc etc. We were both taking care of the kids equally all along. If one was out for an evening, it was no problem for the other to stay in with the baby. The babies (a big difference in age, 6 and 13 now) were equally comfortable with either of us but would of course freak at babysitters. When my ex went back to work after mat leave she worked shifts and I was regularly caring for the children on my own over weekends, evenings or overnights depending on her shift.
We went with shared parenting immediately (our youngest was 3 at the time) because the children would have freaked at any other arrangement.
For you it was different, you have to be your own judge. Is your ex capable of caring for a 1 year old, who is still really a baby? None of us are born with parental skills, not mothers, not fathers. The course for taking care of a 1 year old is a year long and it's called "Caring for a newborn". If he's missed that, then it's a big leap to go all at once.
I'm saying this as a 50/50 parent who believes this works and is better for the kids if the parents are at all reasonable. The parents don't have to get along, they don't have to like each other, they don't have to agree all the time. They just have be able to be civil and co-operate as co-workers. But your ex needs on the job training in this, he needs regular time with the baby, not just when she's clean and changed and happy, but when she's dirty and cranky and throwing up. He needs to be prepared, he needs his home prepared, he needs to be spending the occasional overnight with her so they bond, so it's not a huge challenge for anyone, not the baby, not him, and not you to be away from her.
He also needs to feel with no doubt that he can call you with problems and get advice and not judgement. Whatever your differences, and whatever your fears and insecurities about your baby, you have to be there to help but not make him feel like an idiot if he doesn't know something or can't handle it the first time.
For our 3 year old we went with a 2 day schedule because at a very young age, 2 days is a long time, and a week away from either of us would be too long, for us as well as for him. We did Saturday/Sunday from early afternoon Saturday to Sunday evening, and for him it was like two full days even though it was one overnight. We were all happy with the schedule and haven't had cause to change it.
