Excel。 Weeknum函数。 ＃值！ 错误。 日历

Question

Dear person. As you can see in the picture there is a #VALUE! error when it tries to show some weeknumbers.

Referring to the picture:

Nr. 1. I'm trying to figure out how to show the weeknumbers that have datenumbers in that week

Nr. 2. I'm trying to figure out how to show a blank cell for the rows with no datenumbers in that week

The workbook: https://www.dropbox.com/s/ed6dt022i0yz6py/Calendar.xlsx?dl=0

Help!:)

Answer 1

I think this is the one you want based on weeks from Monday to Sunday

=IFERROR(WEEKNUM(AGGREGATE(15,0,C17:I17,1),2),"")

I have chosen to use Aggregate because it will error out if there are no numbers in the range, so IFERROR will give a blank. You could just use MIN or MAX instead and test for the result being zero. You could also use LOOKUP or HLOOKUP. This might be the shortest way

=IFERROR(WEEKNUM(LOOKUP(99999,C17:I17),2),"")

The week starting with December 31st ('week 53') is really week 1 of 2019 so you could add a separate condition for this.

To fix the 'week 53' issue, I can't do any better than this rather long formula at present

=IF(COUNT(C17:I17)=0,"",IF(AND(MONTH(LOOKUP(9E+99,C17:I17))=12,C17<>"",I17=""),1,WEEKNUM(LOOKUP(9E+99,C17:I17),2)))

which says 'if it is the last week of December and at least one of the days in that week is empty, then the week is week one of the following year'.

This could be further modified to deal with an ISO year where week 1 is the first week containing a Thursday.