If you are a business and set a planned date of st

If you are a business and set a planned date of startup you wouldn't want to move it up.  In this case advertisers (if any) are expecting startup on the 29th.  An earlier start and you advertise for them may be disastrous as if you are retailer you may not product on hand, computers programmed with sale prices, etc.  And if you can't move up the ads with vendors you certainly don't want to incur expenses from starting early and not being able to pay for the start.