I am green with envy
My trees are in full sun. These years HJ, SC and Shanxi li have plenty of of blooms. It is too early to tell if they will set fruit and how well (I sure hope they do).
It amazes me that you are in zone 5 but your fruit tree production, not just jujube, are a couple of weeks ahead of mine. My jujubes just start flowering 5-6 days ago.