You can programmatically find out how long SQL Server has been running by getting this information from the sysprocesses table. Sysprocesses is a table in the master database that contains information about processes running on the server. Sysprocesses is not like an ordinary table because it doesn’t have permanent disk storage associated with it. SQL Server builds the sysprocesses table dynamically whenever a user queries it, and you can’t update it. Here, you check the login_time column to find out how long SQL Server has been running:

 SELECT login_time FROM master ..sysprocesses WHERE spid = 1