Conditional Sum - Two Unrelated Tables

Hello,

I have two unrelated tables. In Table A I have a date column and I could like to add a calculated colum which sums up Work Hours in Table B, depending on a condition.

For each row in Table A, I would like to compare the date in Table A and check if it is between two dates in Table B. I would like this to iterate through all the rows in Table B and only sum up the hours where this condition is true.

I tried this, but it doesn't seem to work:

 Any suggestions or help would be much appreciated.

Thanks!