If the clock continues uninterrupted, it should end at 7:15 pm (California local time). Didn't realize this before when it was first revealed, but that does align with shortly after the LPU event. It's scheduled to end at 5:30 pm. So whatever that event is, the LPU fans will know first followed by the rest of the world?
EDIT: After looking at the timer again, it seems to have shifted a little so I would need to recalculate when it would end. Quick glance, it look like it would end at the 50 minute mark of whatever hour instead of minute 15