Same idea....just transposed...

Try

=SUMPRODUCT(--($F$2:$F$100<>F2),--($G$2:$G$100=G2)) copied down...

adjust ranges to suit your actual range sizes....

If you have a result of 1 or more, then the date is repeated for opposite code...if you have a result of 0, then the "other" code does not appear for same date within range....

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