EASY:
he consistently wakes up between 6 and 6:20 am
E: 7am breakfast, getting ready to leave the house for library/outdoor play etc.
S/A: he sometimes falls asleep in the car or stroller on the way there (around 9am), if, however, I decide to stay home for him to nap, he doesn't sleep at that time.
E:12pm: lunch (his older brother used to go to sleep after lunch, but he doesn't anymore, even later he doesn't sleep, but gets unbearable after 3:30)
(A: 1pm some more play time, if he took a cat nap in the car/stroller)
S:1pm/2pm: PU/PD, usually for about 1 hour until I give up and get him out of his bed or (if he seems even more tired than usual) rock/shush-pat him to sleep or put him on our bed and rest next to him (he then sleeps a 45 minute sleep cycle)
E: snack at about 4pm
A: play outside or take a walk/play with other kids
E:dinner at6
S:7pm, he usually goes to bed without crying, we just put him in his crib
recently:
wakes up between 9:30 and 10pm, crying, PU/PD, give him water,...takes between 10 and 45 minutes
then one erratic waking at night (can't be hunger, though, he eats a lot during the day and for dinner)
Thank you for your advice. This really affects our family life in a very negative way!