You are here

why I am getting e-mail from 1969?

This came up on Facebook, and I thought it worth a quick post here. From time to time you may see e-mail or files with a date of December 31, 1969. What the heck?

The explanation is that many computer systems measure time as the number of seconds since January 1, 1970 12:00 am UTC. (Sort of. Leap seconds make it complicated. See the wik's article on "Unix Time" for the gory details.)

So a time of "0" indicates that date and time -- which in any U.S. timezone, would have been the night of December 31, 1969. (UTC, for most practical purposes, is "Greenwich Mean Time", and so is a few hours ahead of the U.S.)

And if your file doesn't have valid time information attached to it, or your e-mail has a garbled Date: header, the system will treat it as 0, and claim that it's from the dawn of the 70s.

So now you know. And knowing's half the battle.


Add new comment

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
To prevent automated spam submissions leave this field empty.
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Enter the characters shown in the image.

User login

To prevent automated spam submissions leave this field empty.