SUMIFS between date ranges only returning 0 value

I have the following formula in a workbook and it only returns $0. I know what the answer should be, but it doesn't seem to matter what I do, it won't give me the answer I want
=SUMIFS(I4:I200,T4:T200,"VINCE",K4:K200,">=AF101",K4:K200,"<=AF102")

Range I4:I200 - money column
Range T4:T200 - names column
Range K4:k200 - dates columns

AF101 - set date eg 01/07/16
AF102 - set date eg 30/09/16

I know what the answer should be in the cell($68,910.60), but the formula only returns $0.

What am I doing wrong?

Thanks

Try this:

=SUMIFS(I4:I200,T4:T200,"VINCE",K4:K200,">="&AF101,K4:K200,"<="&AF102)

Thank you so much
Works great
Will that work in the following scenario?
=SUMIFS(I4:I200,T4:T200,"VINCE",K4:K200,">="&AF101,K4:K200,"<="&AF102)+SUMIFS(I4:I200,T4:T200,"DNC VINCE",K4:K200,">="&AF101,K4:K200,"<="&AF102)

*** EDIT NVM It works

I was about to ask if you had tried it, but you have! Glad to have helped.