You have now stepped in to the Twilight Zone...
All right, fine, I'll be serious...
This brings me to the crux of the matter. The last date shown on the message is 2 days from now. There's no number of death and there's no GPS coordinates. I have to assume that this upcoming disaster will happen everywhere and that it will affect everyone.
When I was about 20, I turned into an atheist after spending all my life as a devout fundamentalist christian. Now that I am faced with my own mortality as well as the mortality of every other human being on Earth, should I turn back to god or should I continue to deny god's existence? Will "Judgement Day" be a planned event meant as a wakeup call for all of us or will it just be an event, one of many in the universe?
What are the dates? If you say December 21 2012, you might even freak me out.
First things first... Do you have any way to find out who wrote down the series of numbers? If they are still alive (they'd probably be about 60 yrs old) you can interview them and have them recollect what the significance of the numbers were to them.
Start with the simplest explanations and work your way out, systematically ruling certain things out while giving way to the possibility of others.
Are you able to accomplish this?
"The problem with Socialism is you eventually run out of other people's money." --Margaret Thatcher--