Suppose I say "We're moving the 12 PM meeting forward 2 hours", does that mean the meeting is at 10 AM or 2 PM?
If you move a meeting forward, you are scheduling it earlier. See Collins.
There is, however, a lot of confusion about terms like up, back, forward, and out when they are used in this context. As Merriam-Webster suggests, the best way to handle them is probably not to use them at all, and substitute less ambiguous words like earlier and later in their place.