A barrier option where the barrier (trigger price) is monitored for hits only during specific points in time. That means the barrier is inactive for part of the option’s lifespan. The monitoring period can be at the beginning section or the end section of the option’s life.

Within this category of options (partial-time barriers), there are two distinct types: partial-time start options, which have a knock-out barrier at the beginning of the option’s life that is removed at some preset point in time, and partial-time end options (or protected barrier options), which cannot be knocked out at the beginning of their lives.