Restrict SUMPRODUCT to a date range to see if a response target is met

I've got the following data from a legacy system:

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Using the following formula:

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I can find how many were completed within x days, 7 for example. However this is applied to the whole data set. Let's say I wanted to know how many were completed in 7 days in January alone? Is there some way to filter the array to remove the dates I'm not interested before the above formula gets applied?

I'm trying to keep this to a single cell formula, rather than creating hidden/dummy/helper columns to do the calculations for me for various stupid workplace reasons. Resolution to days is fine, hours/minutes is not needed.

Maybe I'm going about this the wrong way?

To aid understanding, what I'm trying to end up with is a stats worksheet that references this data (stored elsewhere and not editable) with something along the lines of the following:

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