Auto-calculate end date range from initial estimate

Who would benefit?

Anyone who uses capacity planning

What impact would it make?

Save time and ease the usage

How should it work?

When the user adds "start date range" and " initial estimate", the "end date range" will be calculated automatically. The other way happens today - the " initial estimate" is being calculated automatically when adding a "date range" - but I think it is more common to know when the task should stat and how long it should take rather than 'know' the end date.