There will be no Mormon church services on Easter Sunday.
Enough said.
It is general conference. PR and recruiting comes ahead of Christ.
You're thinking of Christmas. That's the time that the Mormons celebrate JS's birthday. You are right. JS birthday lasted the whole season.
The very first year of "correlation", we in the Primary presidency were given a script for the Primary children's Christmas program. We had already written our program, and had started rehearsing the songs, and there had been no warning this was going to happen. The correlated script was all about Joseph Smith's birthday--not about Christ of Christmas at all! We protested, but, of course, no one paid any attention to us, and we were forced to comply.
The few Mormon friends I still have, say that Christ is barely mentioned at Christmas or Easter. They say that Joseph Smith has been toned down a bit, and the talks are usually taken from old conference speeches, and are about more secular subjects, like tithing, re-activating members, converting new members, the temple, obedience, attendance, "magnifying your callings", etc.