Uptime. Uptime is a measure of the time a machine, typically a computer, has been working and available.
Uptime is the opposite of downtime. Htop adds an exclamation mark when uptime is bigger than 100 days. Server Monitoring Software - IT Systems Management, Capacity Planning, Application and Server Monitoring - uptime software. W.H.S.R. - Independent Web Hosting Reviews, Ratings & Web Development Guide.