Average per day

Hi, seems too simple but I can't work this out....

I'd like to create a column with DAX that is the average of a column per day.

Sample data

date          value

1/1/2019   1

1/1/2019   2

1/1/2019   1

1/2/2019   1

1/2/2019   1

1/3/2019   10

1/3/2019   1

1/3/2019   1

so the new column would be average per day,

date          value  average

1/1/2019   1        1.33

1/1/2019   2        1.33

1/1/2019   1        1.33

1/2/2019   1        1

1/2/2019   1        1

1/3/2019   10      4

1/3/2019   1        4

1/3/2019   1        4

There is a bunch of calculation I'll do on the average, hence needing a column.

Thanks for any help.