Creating a custom report with a date range in the output

Summary

1-6 days passed SLA, 7-10 Days passed SLA, 11-14 Days and 15 or greater

Content

Hi friends,

I am trying to create a report with incident data where I am checking how many incidents have passed the SLA of 5 days from its date created.I want to create four similar reports that have a range of 1-6 days passed , 7-10 days passed, 11-14 days passed and 15 or greater. Here the SLA is nothing but incident date created + 5 days (its not the standard SLA object). The 5 days should exclude weekends and holidays.I have written a custom script that can give me how many days have passed from the "day it should be closed" but I need to