Holy cow, I wrote a book!
Some time ago,
I discussed several timestamp formats you might run into.
Today we'll take a logical step from that information and
develop a list of special values you might encounter.
Note that if you apply time zone adjustments, the actual timestamp may
shift by up to a day.
All of these special values have one thing in common:
If you see them, it's probably a bug.
Typically they will arise when somebody
fails to do proper error checking and ends up treating an error code as if it
were a valid return value.
(The special values 0, -1, and 0xFFFFFFFF are often used as error codes.)