How many employees at a certain hour

Good day colleagues, Ive searched your forums and others and have not found a definite answer. My dilema is, that I need to know how many employees I have available at a certain hour. Ive tried several formulas and have managed to done half. The problem is that when it comes to 12am to 6am excel wont count all available employees, it sometimes comes out as 0. It happens the same from 2pm onwards. Ive tried, sumproduct, count.if and others. Maybe Im doing it wrong.

Any help is welcomed. Attacehd you will find what Im doing. (my excel is in spanish, in case yours doesnt automatically convert the formula to english)