I don't mean to necro this thread, but it's the only real significant thing I found that seems to correlate to what just happened.
I have a Google Now Reminder to remind me on the 20th of each month to pay my credit cards. This morning, the reminder went off at 9am and woke me up (worked late last night). I went to the reminder to change it from 9am to something that has no chance of waking me up and saw that it was already set to "Afternoon". To my understanding, this means it should have alerted me at 1pm.
I am in EST time zone.
Is anyone else having their issues again and/or can anyone reproduce my same issue?