Countifs values between 2 dates.

[Tdoulis]

This one is doing my head in. I’m trying to build a labour availability schedule which extracts data from a gannt chart and a leave roster and need check availability of a tradesman. To do this I thought the best way would be to do a countifs function with 3 criteria 1) Tradesman Name 2) Start date 3) End Date.
I’m using the formula =COUNTIFS(GANNTDATA[TRADESMAN],$B14,GANNTDATA[START],">="&F$13,GANNTDATA[END],"<="&G$13) but the only value that is working is where there just one tradesman and the start and end date are the same.

Can someone give me a heads up as to what I’m doing wrong.