DATEDIF equation error

[Hamza23]

When I try to apply the DATEDIF equation, I get an error from the program, and I can't solve this problem
and i uploaded two screenshots to show my problem

  

[#2]

am use 365 office
win 10

[#3]

@Hamza23 

Make sure that the first argument is earlier than the second argument.

Perhaps you need to use a semicolon ; instead of a comma , between the arguments?

[#4]

@Hamza23 

[#5]

I have already followed those steps , and it's actually worked .. but i still don't know why this happend . Knowing that i worked this time in new worksheet and changed the region of my windows on labtop to english

thanks alot by the way prof

[#6]

thanks for decleraing sir