It's alot of factors that come to play when talking about a start day, such as training schedule, position effective date, training length, company type and the need for the specific role to be filled. Start dates are usually quicker/earlier when it a urgent need to fill a position or if it's a position that doesn't need much training or a position that's doing on the job training. Sometime start dates can be scheduled months out from the time you actually receive the job offer.