Early Christian historian, Eusebius, said that Jesus’ ministry lasted three years. I agree, and so do a lot of commentaries and people who attempt to harmonize the gospels. However, problems start when we try to make St. Johns account fit with the synoptic gospels; big problems.
I cannot get my svg diagram on to this forum, but here is the link to my timeline for discussion. Let’s see what folks think, and I’ll try to explain my scheme as we go along.