SLA's and Due Date adjustment

SLA's and Due Date adjustment

HI

I have a standard SLA but we have an agreement on some requests that they will contractually completed within 48hours of the final approval.  Obviously if the request isn't approved straight away then this can have an impact on the SLA completions.

Is there any way to set the Due Date from the point the request gets approved rather than the initial SLA target on the ticket?