DIY Blog Tour: Scheduling
For example, if you want your tour to build release date launch, then you want your tour to happen just before and during your release week. If you want to engage readers, it's best to wait a month so readers have time to read the book.
How long your tour lasts depends on several factors, but the most important is being honest with yourself. The tour is not something you turn on and let run. It requires your active participation. Don't plan for a three week tour in December if you know traveling during the holidays keeps you away from the internet for most of the month. Also, keep in mind that the more tour stops you have, the more unique content you need to provide.
By realistic with your calendar and work load to pick a time that allows you to be a full participant in your tour.