Date Different return wrong value

Hi v-achippa vojtechsima ronrsnfld ralf_anton cengizhanarslan ,

Thank you for your assistant and support.

I'm able to populate the Day Diff correctly with your guide. Here is what i did:

1. Transform both Doc Date and GR Date column as some of records may contain text

= Table.TransformColumns(
#"Reordered Columns",
{
       {"GR Date", each
                if _ = null then
                       null
               else
         let
             t = Text.From(_),
                   parts = Text.Split(t,"/")
             in
                  #date(
                  Number.FromText(parts{2}),
                  Number.FromText(parts{0}),
                  Number.FromText(parts{1})
                   ),
                       type date}
                          }
                          )

2. Day Diff

= Table.AddColumn(Custom3, "Day Diff", each if [GR Date] = null or [Document Date] = null
then null
else Duration.Days([GR Date] - [Document Date]))

TQVM