Linux is known to be highly stable and reliable. Personally, I have proven this several times already pitting Linux against Windows-based servers.
Let's have some fun today and see who has the longest running linux system. Those maintaining servers will surely get impressive results but hey, this is all for fun (and to prove that Linux is indeed stable and reliable).
What you need to do is simple – just type "uptime" on the Terminal and it will display some information similar to this:
20:21:28 up 6 days, 5:47, 4 users, load average : 1.90, 1.46, 1.36