how to count the unique days some one worked in?

[siamandm]

Hello All
i wan to know that the number of days that someone worked in, for example in this example below
John Doe worked in two different day so the number of days is 2, so how to write a function for this purpose please?

Screenshot 2020-12-24 094254.png

i have attached a sample data,

Regards

[HansV]

In M7 as an array formula confirmed with Ctrl+Shift+Enter:

=SUM(--(FREQUENCY(IF(($B$2:$B$15=K7)+($C$2:$C$15=K7),MATCH($A$2:$A$15,$A$2:$A$15,0)),ROW($A$2:$A$15)-ROW($A$2)+1)>0))

Fill down.

Remark: Mark Polo worked on both dates, so the formula in M9 returns 2, not 1.

[siamandm]

Thanks a lot, working very good ...

[p45cal]

In the attached, if you right-click the table at cell I19 and choose Refresh the table will update itself. It will cope without change if you add more name columns or date rows to the table at top-left of the sheet.

[siamandm]

In the attached, if you right-click the table at cell I19 and choose Refresh the table will update itself. It will cope without change if you add more name columns or date rows to the table at top-left of the sheet.

thanks a lot, it is very useful

Regards