Uptime

Return uptime (time since last restart) in the format hrs:mins.

OS version: OS X

set up_time to do shell script "uptime | cut -d ',' -f 1 | cut -d ' ' -f 4"
display dialog ("This machine has been " & up_time & " (hrs:mins).") buttons {"OK"} default button 1 with icon 1 giving up after 20