Maintenance email scheduled for the past?

We received an email today that maintenance is scheduled for our address on "01/21" which is assumed to be January 21st, three months ago.

There is no contact method on the email for us to easily verify if this was a valid email or if there is a correction to the maintenance date.

The only option is to "Confirm mobile number" which we are not going to do in the event this is not a legitimate email; Comcast/xfinity has our current mobile number already.

Any thoughts or similar experiences?

(I'll add that given the number of folks who work from home, any scheduled internet maintenance during business hours is a problem. No internet at night is annoying -- but no internet during the day can be a serious challenge if we have online meetings but our area has terrible mobile coverage.)