Adding more planned hours with contouring

One of the team members has come to me with an interesting question. If she plans a request and set the daily hours for it. Imagine she plans 3 hours in a week: 1.5 for Monday, 0.5 for Wednesday and 1 for Friday. But on Thursday she receives new information and has to increase the planned hours to 5. If she does so, the plan for the whole request will change in the application to 1 hour each day starting on Monday so she will have to replan the whole daily hours to put the 2 additional hours only from Thursday to Friday.