RPers in general generally don't go looking for places to RP on specific dates. Muses are often fickle creatures, so chances are that someone who would join might not be in possession of an active muse at such a registration date. Far easier to have a demand on introduction thread and/or approval/invite from another user with >n post count. The latter would help those who get panicked by the idea of writing such a thread join. If you need to have been registered for 1 months and have at least 200 posts to approve a user, chances are pretty high you're not a spambot. We thought of suggesting higher numbers, but not everyone posts a lot even while being active. if a bot manages to get to 200 posts and 1 month of life, its a pretty good bot. Our cost-benefit evaluation of just 1-3 days per month with registration puts the costs at far higher than the benefits.