Another play to try ..

In sheet: Data
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Assume data starts in row1 down, col C contains dates & col D houses
formulas filled down (in D1: =weeknum(C1)) progressively

Use an adjacent col, say col E?
Put in E1: =IF(C1="","",IF(COUNTIF($D$1:D1,D1)1,"",ROW()))
Copy down to say, E200, to cover the max expected range in col C

Then in sheet: Summary
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Put in say, A2:

=IF(ISERROR(SMALL(Data!$E:$E,COLUMN(A1))),"",
INDEX(Data!$D:$D,
MATCH(SMALL(Data!$E:$E,COLUMN(A1)),Data!$E:$E,0)))

Copy A2 across 104 cols to say, CZ2,
to cover 2 years worth of week#'s

A2:CZ2 will be progressively filled
with the week# from "Data" as desired
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Rgds
Max
xl 97
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Singapore, GMT+8
xdemechanik
http://savefile.com/projects/236895
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