If a baby is tired, you can't keep them up, and if they are not tired, you can't force them to sleep....so you just have to follow their lead! One thing that helped us fall into a routine, was I took a week where I didn't run errands...We just hung out at the house, and by Friday it was like we were on the same page as to what to do (play, sleep, eat, relax). Of course things never happened at the exact same time each day, but around the same time, yes. I think that running errands and being out and about does make it harder to keep a "schedule" going.
I don't think it's possible and/ or reasonable to expect LO to adhere to a schedule at this point. Just follow his lead. Babies fall into a routine on their own.
People often use schedule and routine in the same way. Schedules don't work but routines can, to a degree. EASY is a great method to try to follow (Eat/Awake/Sleep/You Time) but some days it goes right to hell.
Schedule... routine... you're not going to have much success with either at this age.
Once you find LO's day becoming predictable you can implement routines. Overtime LO will set their own schedule. And that schedule will change 19 million times between now and his/her first birthday.
I'm still waiting for DD2 to become even remotely predictable... but I think DD1 prevents a lot of that.
Re: Starting a schedule
DD2 8.22.13
MMC 1.4.17 at 16w
Expecting #3, EDD 1.29.18