Date Calculation Election Schedule

My efforts to tweak the field codes to calculate a date range hasn't been successful.

What's needed is an automatic update for the beginning and end of an organization's three-year election cycle. The formula I need to begin with is

for the start year:

{DATE (yyyy) - MOD({DATE yyyy}, 3), \@ "yyyy"}

that is, the current year less the MOD for the current year divided by 3, so that for 2013, 2014, and 2015 the result would be "2013."

The end of the election cycle would be that number plus three - "2016."

In 2016, the calculation would update so the two numbers would be "2016" and "2019."

It doesn't matter whether the result is a date or a 4-digit number.

I think I'm probably not extracting the year as a number to run this formula on. Any suggestions would be most welcome!

Sincerely,

axsc