I may want to take a look at https://github.com/osTicket/osTicket/pull/419, it contains SLA changes which changes SLA based on working hours + you can set to recalculate SLA based on last response.This pull adds a "Revolving" option to SLAs that will base the ticket overdue trigger on the ticket.lastresponse date instead of ticket.created or ticket.reopened. It currently will not mark tickets as overdue if they are answered and waiting on a response from the requester.Beware: It is semi-compatible with 1.10, thus you will need someone with good php knowledge to "slightly" fix it, but it is doable.