I've been exploring the discussions around Growing Degree Days (GDD) for Maple Trees. Ohio State University has a GDD calculator based on location and how many GDD days there are for Maple Trees. But the calculator is only for Ohio.

I looked at Michigan State University, but their GDD calculator only started in mid-February, and mainly concerns the emergence of pests related to blooms.

Are there any good GDD calculators for Maple Trees in Michigan? Silvers typically open first correct? But Sugars can take much longer, correct?

The reason I ask is I've just really started identifying the maples in my sugarbush. Most are sugars. The few silvers I have all have swollen buds and we pulled our taps last year based on our silvers, not our sugars.