sum() will copy the custom formatting!

[lezawang]

Hi
I custom formatted cells A1-A10 with #;#;-;

and when i wrote B1=sum(A1:A10), excel changed the format of B1 to same custom formatting of A1-A10, why is that? does that apply on all functions?

 

[thisoldman]

Excel tries to be helpful. It can be annoying when it automatically interprets what I want as text and makes them dates: when 6-17 becomes 17-Jun.

You are aware that your custom formatting hides text entries?