Window of time = a time frame that is given ex. You: What time will you arrive at my house? Me: Somewhere between 10 and 11 o clock. The window of time is between 10 and 11 o clock.

Thank you Jared!

The phrase "window of time" suggests an opening (hence window) of limited duration during which something can be accomplished. For example, "Somebody dropped out of the course, so you better apply quickly, because my guess is you only have a three-day window of time." Similar to the phrase, "window of opportunity." The idea is, if you don't act, the window closes, and goodbye opportunity, as we have all experienced. :-) -- Jared Israel