Is it possible to change the schedule of an SLA without recreating the SLA?
The schedules or business schedules are part of an Offering, thus not directly part of an SLA. An Offering is associated with an SLA when the SLA is first created. You cannot directly change the Offering that is included in the SLA, though you can replace the Offering with another compatible/similar Offering.
You can associate a different Offering with an SLA after it is submitted. The new Offering can include different metrics or breach values without invalidating the existing SLA definition. A different schedule can also be associated with the new Offering. The new Offering must be similar to the old Offering, meaning that it must have the same offering components because of the specific resources already defined in the SLA that are associated with the offering components.