MySQL - 更改一行的时间值以匹配同一表的另一行的时间值

I have several consultants who record their job start/end times. Because they have two-hour minimum fees, I need to make sure that I properly calculate their job times. The problem arises when they have consecutive jobs on the same site, with idle times ranging between 15 to 60 minutes between jobs. I have several consultants who record their job