Use the template
Code:
program:
test(check_yes_no('#mybool', 0, 1, 0), test(field('#mydate'), 'Yes', ''), '')
Be sure to change the lookup keys to the ones in your database.
Note that this template returns "Yes" or empty. If you want "No" then change the empty strings ('') to 'No'. You can also distinguish between the Yes/No column set to False when there is no date by changing only the first ''.
You might want to check the box "Show checkmarks" in the definition of your composite column.