Yes, it is possible.
Here's the code if someone else is looking for it:
[cb:if cb_dateto = "0000-00-00"][cb_datefrom][/cb:if] [cb:if cb_dateto != "0000-00-00"][cb_datefrom] -[cb_dateto][/cb:if]
I have only done this in the date format that we use, so it might be that the dateformat has to be changed.