Group values

Sorry Borntoreport,

   I skipped your question about the conversion. To solve it you have to:

1) Split the column by number of characters ( Transform -> Split columns -> By number of characters) with:

    - "4" as Number of character (to indicate the year)

    - "Once, as far left as possible" as Split

2) Re-split the right column by number of characters with:

    - 2 as number of character (to separate the month from the day)

    - "Once, as far left as possible" as Split

3) After that you have three columns (year-month-day)

4) All you have to do is merge the columns (Add column -> Merge columns) with a custom separator/tab/space (as you want)

5) Finally you select the column and change the data type into date.

I remind to you that I'm not an expert, certainly there is a DAX formula to do it.