In the leaderboards, we display your Experience points (XP) broken down and displayed as Yearly, Monthly, and Weekly. These are based on the past 365 days, the past 30 days and the past 7 days respectively. So if you were very active six days ago, but then inactive for a few days, your running total for that Week, Month, and Year would change accordingly. Your total XP will always be displayed in your Member Profile and will never go down.
The below chart will illustrate how your activity over a fourteen day period would be displayed over consecutive sets of seven days. Note how your XP for the past Week fluctuates day to day. The same would be true for any 30 days or 365 day period.