Why did my YouTube watch time hours decrease in the Earn tab?

It can be quite frustrating to see your public watch hours drop, but this is a standard occurrence within the YouTube Partner Program tracking system. The "Earn" tab operates on a strict rolling 365-day window, meaning that watch hours gained exactly one year ago today are removed as new hours from today are added. If your recent viewership is lower than it was during the same period last year, your total will decrease. Additionally, YouTube excludes watch hours from private, unlisted, or deleted videos, as well as views from YouTube Shorts and ad campaigns. It also takes 48 to 72 hours for the system to validate and update your stats, so a temporary lag or the removal of "invalid" bot traffic can cause the numbers to fluctuate. Focus on consistent uploads to ensure your new gains outpace the expiring data from the previous year.