[Minor49er]

They shouldn't be "fake" though. That implies that the deadlines are meaningless

Telling a team that "the deadline is May 8th, but the _fake_ deadline is May 1st" doesn't do anything for motivation, and could actually backfire since it's arbitrary. Saying something reasoned like "we need this delivered on May 8th, but we need feature development to be complete by May 1st to allow for a week of testing and deployment rollout" gives meaning to the "fake" deadline and sets up some expectations for what will happen once the "fake" deadline is reached

Of course, with proper planning, these cease to be "fake", so I guess the point is moot