Displaying People With Unassigned Efforted Work

Has anyone devised a way of seeing when someone isn't assigned any "efforted work" (has zero hours displayed in their workload)?

What I’m hoping to accomplish is some sort of reporting based off the workload views.  I need to be able to select a user and a date range and have the system generate dates of “availability” (or something like that, that shows ranges within my search parameters where the user has no efforted work assigned).

For instance:

• “Joe” has efforted work assigned during the following periods between now and the end of the year:
• 07/28/2025 – 08/13/2025
• 09/01/2025 – 09/05/2025
• 09/15/2025 – 09/19/2025
• 10/13/2025 – 12/31/2025
• Without “manually counting empty blocks”, I need to know when “Joe” doesn’t have any assigned effort between 07/28/2025 and 12/31/2025.  Which would be:
• 08/14/2025 – 08/29/2025 (in an ideal world, this would also tell me that it’s 12 working days)
• 09/08/2025 – 09/12/2025 (in an ideal world, this would also tell me that it’s 5 working days)
• 09/22/2025 – 10/10/2025 (in an ideal world, this would also tell me that it’s 15 working days)

A quick point of clarification: but the system should be “omitting” non-working days (weekends and holidays, etc.) as no efforted work will ever be assigned these days.

Many thanks.