Answer: 1. When was the SQL Server Service Started ?
SELECT sqlserver_start_time 'SQL Server Started at' FROM sys.dm_os_sys_info
2. When was the TempDB database Re-Created ?
SELECT create_date 'SQL Server Started at' FROM sys.databases WHERE [name] ='tempdb'
Both the query have some difference on it's Time, Because, The Tempdb database will be Re-created after the SQL Server service started.
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