Hi silly quick question. I want the year from a date field '15' at the moment it is giving me 20 as in 2015

lastc(year(date),2)

Year() return a 4 digit year i.e. 2015 and as all return values are treated as text in conversion that will be read from left to right when you convert it to two digits.

So if you only want the last to digits you need to use the string function LastC() to cut them out.