Opinions/tips on the dove gradual tanning lotion?

I recently bought the light to medium version of it for a trip i have in a week and im wondering how far in advance i should start using it or if its even good at all. So far i did a small patch test and it looks basically the same (im super pale for reference), im guessing i just need to apply more product? Also, how long does it usually last? my trip is 5 days long