I think your answer is in the sysperfinfo table. I'm struggling to remember exactly how to determine it. It's not a straightforward number as I recall, but the denominator (or base counter) for another entry in the table.
Also, take a look at sp_monitor. This gives you total number of seconds (SQL, IO and Idle) that a server has been up.
Check out SQL BOL on sp_monitor.
Originally posted by andyabel
Is there a system table (or metric) that you can look at to determine the date/time the SQL server instance came up? Thanks