Given a date between 2010-01-01 and 2099-12-31 as three integers (please state your order if not
[year,month,day]), answer with Tesco's corresponding five-digit Burger Relish Best Before End date number.
The format is simply the last two digits of the year, followed immediately by three digits representing the day of that year, between 000 and 365.
Cookies if you can do this using only numeric operations and comparisons. You may put such code separately from your golfed code, if it isn't also the shortest code you have.