I started a new job recently, and my boss works remotely, so an onsite senior level employee sort of fills the roll of my boss. There is a several-hour long meeting tomorrow in the afternoon that goes well beyond the hours I usually work; I am salaried but usually try to keep certain hours unless something important comes up.
In an email to me and a couple of other people my boss stated the senior level employee needs to attend the meeting, but didn't mention me. The organizer of the meeting didn't even include me on the invitation, but my coworker forwarded me the invitation. I know that my coworker will ask me in person to attend the meeting, but I really don't want to spend hours in a meeting that will require me to stay a couple hours late and doesn't sound like it actual is important that I attend.
I don't want to just come right out and say "No, I'm not going" because as a new employee I don't want to come off as rude or jeopardize my position. How do I politely say I'm going to skip this meeting?