If you have tasks that have no dates in them already, we would love a "planning start time" and "planning end time" field. This is most useful in Gannt, where we can identify where all our projects currently sit, and plan new projects around them. After we plan dates, we have to confirm that those dates work for the client, so they aren't technically locked in yet.

The ability to add planning dates that make the task appear on the Gannt, Calendar, etc, as a transparently lighter colored version, indicating that they are not confirmed would be great!

Then possibly have the ability to "lock in" the dates and it moves the entries from planned start and planned finish to "start date" and "end date."