Those little comedians.
Here's a quote of what they did from Mercury News:
No question, Google is serious about its fun. Its Gmail gag this year promised ....(are you ready?)..........
the ability to pre-date e-mails you send. (Miss a birthday? Pre-date your e-mail greeting and it will get there days ago.) Google's site explained that the technology relied on "an e-flux capacitor to resolve issues of causality." It helps to be versed in the grandfather paradox, the Gmail site explains while pointing to a brief reading assignment.
I think that's too funny!!! e-flux capacitor.
Here's another one:
In a startling new investment in time futures, it seems as though Google can now backdate emails so that you never have to fret about an unsent email. You get ten uses. Any more than that "would cause people to lose faith in the accuracy of time, thus rendering the feature useless."
FUNNY!!!!!