Reference Gantt Chart from Multiple Tabs to Create Master Schedule for Specified DateRange

Hi,

I'm trying to reference data from multiple tabs ("cities" tabs) to create a "summary" tab. This summary needs to list which employees are available within a given date range (as defined in column H yellow cells on the summary tab).


Cities Tabs
- Employees are listed in their respective city tabs, along with a gantt chart whether they are booked or available each week (blank squares indicate availability).


Summary Tab
- This should pull info from the cities tabs, and list the blank weeks for each employee between the date range in column H (yellow cells).

- The red text in this tab is that expected values -- how would I automate this?


Any insight would be greatly appreciated!!!

Thank you!