Guidance times vary such a lot at 12 months with some LOs doing 2 naps and some already moved to 1 nap
Average A times- BOOKMARK ME! Mine had moved to 1 nap at this age so his A will have been something like 5 or 6hrs first A, 2hr nap, 4 or 5hrs A then BT. He did a 12hr night for a while when we dropped to one nap but his usual night was more like 10.5hrs so our A times were always on the long side to get through the day.
It's often helpful to move to set nap and BTs with one nap rather than moving them each day.
If your LO will tack on at night then you could see something like a 4.5hr A either side of a 2hr nap and EBT to give a 13 hr night - some will even do 14hrs over night for a while.
Hope this helps.