An example of how to deal with dates (more info here):

var day1 = new System.DateTime(2010, 3, 12); // Year, Month, Day
var day2 = System.DateTime.Today;
var timeframe = System.TimeSpan(8,0,0,0); //Days, Hours, Minutes, Seconds

print(day1); //output: 03/12/2010 00:00:00
print(day2); //output: 03/17/2010 00:00:00

print(day2 - day1 + " < " + timeframe + " ?"); //output: 5.00:00:00 < 8.00:00:00 ?

if(day2 - day1 < timeframe) {
  print("Within time period");
} else {
 print("Time period exceeded");
}