What could cause all major cell phone providers to experience outages that began at the same time in the same day?

A solar flare seems unlikely, since WiFi does not seem to be effected (for me at least).

Routing issue maybe?

One possibility: it’s all just T-Mobile, but people are bad at reporting. For instance: if a non technical person tries to call a t-mobile number from their Verizon phone, and experiences an “outage”, they may report this as a problem with their own phone rather than understanding that it was on the receiving end (and knowing to try to call other carriers).

This could also explain problems with Facebook messenger (if the T-Mobile outage is effecting data). It’s not a problem with messenger etc. it’s just that messenger is the service that some T-Mobile customers are trying to use and having it not work. So they report it as a problem with the black box they know as their phone.

That or we are getting hacked. And if that’s the case then buckle in and charge up your ham radios.