The phrase "time span" refers to the amount of time or duration between two specific points or events. It tells us how long something lasts or how much time passes between a beginning and an end. Full definition
It shows a definite increase in the emission of carbon in the last 200 years of a 1000 year time span from fossil fuel burning by humans in the northern hemisphere. (hubpages.com)
When considering only R&D jobs and the shorter time span of 2002 to 2003, the statistics looked a little worse. (sciencemag.org)
I never could have imagined that I would be going to a gym regularly, even over just the short time span of a month. (therandomwritings.com)