time.php ("my Time Page") source code
The time shows me that the web server and php are working. A ping only tells me that the machine is up; the machine can be up and the web server not up. I have a php header() function in the code that gives the time and prompts a client to fetch the page even if it's cached.
I often call the time page "by hand" through a browser. I also wrote a client-side script that uses the time page to check for life and sends me a text if it fails.
For those of you who aren't programmers (or play with sysadmin stuff), I don't live in New York. That's just the large reference city for USA Eastern Time--the time in New York is the same time as where I am. The UNIX Epoch is the number of seconds since January 1, 1970 at 00:00 GMT.
Another reason for this page is that I'm a bit obsessed with time--accurate clocks, the astronomical definitions of time, etc. As of December 4, 2010, ntp has been running for days, and the time is pretty dang close to accurate.
Note that my robots.txt blocks ("Disallow[s]") the time page because it would be pointless for the search engines to have to refresh the time.
Some times are right-justified because they more closely match my Ubuntu and Windows desktop clocks.
I want to leave the text below where I wax on about AWS. I'm having fun with root access in the cloud.
As of November 29, 2010, ntp is running, so hopefully it will be accurate time going forward. The system was very accurate before I installed ntp, although I suspect it will take some time and/or a reboot to get ntp even better synced. I plan to reboot in a few hours. (More precisely, start another AWS EC2 instance from an AMI created from the first instance and reroute my elastic ip address to the new instance.) [I did indeed do this soon after that--hours later.]
After 11 years, I'm removing the "life check" from my home page. It was superseded long ago. For years there have been a number of widgets on my site that I use all the time, so I know when it's up and down. Thankfully it has been down very, very rarely all this time. It's still on AWS.
I have to laugh about installing NTP. Boy have I gotten obsessed with time accuracy since then.