A news broadcast in  Day 7: 8:00am-9:00am  confirms that Season 7 takes place 65 days after the events of 24: Redemption. Supposing that Inauguration Day took place on January 20th as it does in the real world, this would place Day 7 on or around March 26th.
The average GPA at George Mason University is 3.66. This makes George Mason University Strongly Competitive for GPAs. (Most schools use a weighted GPA out of 4.0, though some report an unweighted GPA. With a GPA of 3.66, George Mason University requires you to be above average in your high school class. You'll need a mix of A's and B's, with a leaning toward A's. If you took some AP or IB classes, this will help boost your weighted GPA and show your ability to take college classes.
Discussion of George Mason's Admissions Standards: Roughly a third of applicants to George Mason University don't get in. Successful applicants will need strong grades and, in many cases, solid standardized test scores. George Mason has test-optional admissions for students with a GPA of 3.5 or higher and a class rank in the top 20%. In the graph above, the blue and green dots represent accepted students. You can see a pretty clear division at a 3.0 GPA - very few students with a lower average were admitted.