How to count leaves for each date of the month

Hey All,
I want to count leaves for each date of the month. please see the attached excel sheet and help me..
Thank you!

Working fine but how can I count the substitute drivers as only one e.g. the driver Alberto and Brant must be counted as only one time as they have two schools but leave must be counted only one..

Try this ...

=SUM(IF(($A$2:$A$265=$I2)*($D$2:$D$265=J$1),1/COUNTIFS($A$2:$A$265,$I2,$B$2:$B$265,$B$2:$B$265,$D$2:$D$265,J$1)))

Enter with Ctrl+Shift+Enter.

thank you Phuocam working great, and I would appreciate if you explain the "1/" part in the formula...