Is there a was to start a flight Schedule like a week after the activation to give a chance for the Reservations to come in?
There are only to ways to activate a flight schedule: immediately or with a 3 days delay (much better because there are 3 days left for booking)
There’s no way to do it longer than three days?
No … 3 days is the maximum. If a route dosent work you have a few choices to look at. Have a look if your Price for the route is about the same then your competetors (if there are any). Then look if you have a good service level. Look about the timings when you depart if you have connecting passengers. If not, do some adjustments … and/or try if an Interlining will help you out. Also have a look in the ORS. No Competition could be an indication that the route is not profitable. If you can not get enough passengers after 3 days and everything else is OK then its time to look for another destination …
and activating it more than three days in advance, even if possible, wouldn’t make any sense as pax only book up to three days in advance