using Sumif/Sumproduct across multiple sheets

Hi there,
I m having trouble with a simple formula where on my master sheet, i have 2 columns. One with the data and one with a value.

I would like to a formula which will look at the dates/value on other sheets which will then tally up the number according to the date.

Do i need to use an array of some sort? I have been messing about if the sumif statement but it doesn't work across multiple spreadsheets.

Any tips or help would be most appreciated.

yes sir, it is

Thanks Champ, that did the job. I was looking at the wrong formulas to use. this works well.