The phrase "predetermined period" means that a specific amount of time has been decided or set in advance for something to happen or last. Full definition
A universal life insurance quote calculator gives parents the opportunity to compare premium cost to expected cash values at predetermined periods. (growingfamilybenefits.com)
After the introductory period expires, the interest rate is subject to adjust at predetermined periods, usually every six months. (annie-mac.com)
Not only are we demonstrating discipline to focus on communicating with God when we intentionally deprive ourselves of food for predetermined periods of time, but we are taking power over basic physical desires, and instead becoming reliant on Him. (relevantmagazine.com)