calculate measure datediff

[pjpreddy2]

So I'm trying to calculate the number of days for this year, meaning 2/28/2018=the 58th day of the year.  I'm using Date Diff, but I keep getting a weird return.

I've tried:

DD = (DATEDIFF(1/1/2018,TODAY(),DAY))

and

DD = (DATEDIFF(TODAY(),12/31/2018,DAY))

both return a value of +/-43,159.

Any ideas on how to fix this?

PJ

[pjpreddy2]

What I'm ultimately trying to do is calculate what the previous year did on our current date, meaning if 2/28/18=$10,000, I want to see what last year did on the same day.  SO I took the average daily balance from last year and wanted to multiply it by the day, to get the day's average. 

Might be a better way to do this so I'll take suggestions, thanks!!

[Zubair_Muhammad · Accepted solution]

@pjpreddy2

Try this

DD = DATEDIFF(Date(2018,1,1),TODAY(),DAY)