one nap

Dominique • Myles John 3/8/16. Micah Robert 6/29/17 baby girl due 10/8/20
Mamas who are down to one nap, what time does you lo wake up and go to bed, go down for a nap and how long do they sleep for during their nap? 
Trying to see if my son if going through a phase for not taking a long nap or if I'm keeping him up too long/not long enough??