The average decision time of math PhD application (Brandeis, Tennessee, York, SFU) I've applied for the math PhD program for the upcoming Fall 2018. The schools I applied include Brandeis University, University of Tennessee, York University and Simon Fraser University. Since it has already been about 10 weeks from the deadline and I have not heard any news from them, I would like to ask anybody with experiences of applying the math graduate program of the above schools: What is the average decision time of the schools I mentioned?

I am struggling with this since one high school in my country is inviting me to be their math teachers, and I need to sign a one year contract if I accept. It's impossible to let them wait for months for my response. Or anybody can give me some advise on this issue?
For most American grad schools, April 15 is a significant date for admittance offers. 

Here is the relevant link about the April 15 deadline. In essence, students who receive offers for grad school admittance are allowed to wait until April 15 to respond. What can happen is that students who receive offers sometimes wait until the last minute to decide, and thus the grad schools don't know if they have enough slots to offer someone further down their waitlist until around April 15.

Thus, I think the latest you might get an offer from a grad school is April 15, or perhaps a day or two later.