Mine used to go to sleep around 10pm but over the past few weeks she's been going to sleep earlier and earlier. We are putting her down around 8pm now. I think as they get older they have less day time naps or shorter day time naps so they're more tired in the evenings x
You could try starting the routine slightly earlier x
Go by baby's cues. Mine doesn't get to nap much because of having toddlers who wake him so he's asleep by 6.