This subject has appeared in the past several times with various approaches being discussed but none of them are satisfactory. I'm raising it again in hopes that it will get some attention. The implementation seems like it should be straightforward.
Tasks have two fields to capture the min and max estimate of the time required to complete the task. These fields roll-up when the tasks belong to a project but do not roll-up in views. I would find it very useful if these fields rolled-up in views to the group level(s). In my particular case it would be useful to have the time of tasks roll-up to a day in order to see if that day is likely to be overloaded and tasks should be redistributed or to roll-up to context to see how much time is required for that location/thing represented by the context. Given that a count of tasks within the grouping is already rolled-up it would seem that it should be straightforward to roll up the Time Required Min and Time Required Max fields.
Current View

Desired View

This post is from 2006 and alludes to a planned feature for this specifically.
Thank you for considering.
BR,
David