How many days after New Years can you pop fireworks?

well if you had a birthday coming up you could use them then or any special ocassion really you are alound to use them any date as long as you are not useing them every day or if you are in a park with out a licise or permistion to do so but you could use them on bonfire night but i am not sure if fireworks have a sell by date of some kind but if you dont you could use them then or on dwalii the festivel of light so you could use them when ever as long as its night time and you are in a place were you have permistion or your own back garden :D