Can I Stay In The Philippines For 59 Days Without A Visa?

I have a valid International Passport. I will be traveling to the Philippines in October. The country entry is for 21 days & their maximum stay is for 59 days. Upon arrival, it is to my understanding that the Immigration must see on my round-trip ticket that I will be leaving in 21 days. Can I book my round-trip ticket for 59 days & stay for those 59 days even though the Philippine Immigration needs to see that I must leave in 21 days?