Relative Day DAX

Hello everyone, I need to create a column in a date table that show the relative day Number 

for exemple if the date of Today is 09/03/2017

If the day chosen is 09/03/2017 than Relative day Number = 0 

if the day chosen is 10/03/2017 than Relative day Number = 1

if the day chosen is 08/10/2017 than Relative day Number = -1

I already calculate the Relative Year Number = 'Dates'[Year]-YEAR(Now())

the Relative Month Number = 'Dates'[Month]-MONTH(Now()) + 12* 'Dates'[Relative Year Number]

and the Relative Quarter Number = 'Dates'[QuarterofYear]-MONTH(NOW()+2/3)+ 4* 'Dates'[Relative Year Number] and it's working.

Now I am trying to Calculate the Relative Day Number using the same methode  however - I can't figure out a way to count the number of days for each year and can't found a function that returns the number of Today of year ( a number from 1 to Number of days in the year)

Is there a way to create this in Power BI - using DAX (which I'm not familar with at all)

Any ideas, suggestions or points in the right direction - would be greatly appreciated!  

Thanks!