Changing the date returned by CurrentDateTime

I am new to expressions in Ignition.
I can format the string returned by CurrentDateTime by using,
dateFormat({[System]Gateway/CurrentDateTime}, “MM/dd/yy”)

Now what I can’t figure out is how to change the value returned.

Example: the string above returnes the current date (06/25/14)
What I want to display is the date for yesterday i.e. (06/24/14)

How do I change the value of the date returned??

You can use the datearithmetic function.


Thank you very much. Just what I was looking for.