A Question about ribbons

Just recently I have bought the package that contains 120k GP+ Hazard Name Card (30 Days). I still have about 16-20 days left on that name card. If I were to buy that package again right now, would that just add 30 more days to my current Hazard name card or would the timer start ticking on the second one immediately and I would be wasting some ZP. I mainly want to know if I need to wait until my first name card runs out to get the full 30 days on the second one.