How to make countifs work correctly

I have two tables.

The table that is being counted has a "Start Time" and "End Time" column.

The other table , that is counting, has a "Start" and "End" column, already formatted for every 30 minutes for every day.

All of the these columns are datetime fields.

I have the following, but this is not working correctly. Any ideas on how to fix this to count in between or every 20 minutes of the start and end columns?

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Try

COUNTIFS(Table_Project_and_Task_Database.accdb[Start Time],">"&[@Start],Table_Project_and_Task_Database.accdb[End Time],"<"&[@End])

Thanks for help, but I messed something up again. I have to think about this logically and could use some more help.

The table that this is counting, it needs to count this if the project time is anywhere within that half hour, or time period notated on the table that is doing the count. Right now, I thing the whole thing, the "Start Time" and "End Time" column have to be between the "Start" and "End" columns. So if something ends 5 minutes before 7 am, if will still be counted. (Does that make any sense). It will count if it the "Start Time" and "End Time" columns fall anywhere between the "Start" and "End" columns.