How to find when SQL Server started using TSQL?

Many times we need to find this small bit of information. The easiest and most obvious way is to refer SQL Log where the startup time is recorded. But if the SQL Log is recycled, this information may be flushed out (missing).

In that case, the easiest workaround is to find when Tempdb is created. Use below code to find out the exact time when SQL Server started (in other word, when Tempdb is created) using TSQL:

USE MASTER
SELECT CREATE_DATE
FROM SYS.DATABASES
WHERE name = 'TEMPDB'