No, I didn't login during that time period. Is there a minimum requirement for logins before the number changes?
Your active time will be counted from your real active time spent on the forum.
What does it mean?
It means that even if you log in your account on a browser, then switch to other page to do other things. When you come back 4 hours later, your total log in time won't be added up 4 more hours. Your active time is what you actively use the forum, scroll the mouse, scrape data, make posts, etc.