WORKDAY_DIFF returning Error

[MegFox]

Hello all, I am trying to use the WORKDAY_DIFF Formula but it is returning #ERROR and I am struggling to determine why.  The IF,AND piece is working, the WORKDAY_DIFF is not (on its own or with the rest of the formula). 

IF(
  AND({DateSubmitted}, {DateCompleted}),
    WORKDAY_DIFF({DateSubmitted},{DateCompleted})
)

My fields are set to ISO dates. DateSubmitted is the Created Time auto value, and the DateCompleted is a formula - 
IF(Status="Done",NOW())

Any help you can provide would be much appreciated. Thank you! 

[Brian_Swanson · Accepted solution]

Good Afternoon @MegFox! 

This would likely be an issue with time zone.  In the Date Submitted Field and Date Completed Field check to make sure that you are using the same time zone.  

[MegFox]

Yes! That did the trick, thank you so much!