There is a street starts from point A and end at point B. It takes 30 minutes to reach from A to B and from B to A. One person want to go from point A to B but exactly in the middle of the street there is checkpost with security guard. The security guard doesn't allow anybody to passthrough the street and returns back the person.

It takes 15 minutes to reach the checkpost from either point A/B. And the security guard just go for lunch at 1.00PM and returns back exaclty at 1.15PM.

How a person can go from point A to B?