dear Aditya

I am fairly new to Servicenow and I have a similiar need to caculate sla based on ticket open time.

I was wondering if your solution is still relevant  in London release, can you confirm that ?

Also I tried to import xmls you have provided for SLA and schedule but it didnt work on a developer instance.

Also I am unsure about the sample script your have provided, where exactly that script should run ?

in a business rule ?

I hope you have some time to clarify this 🙂