Question

I have the next simple code…

Console.WriteLine(default(DateTime).Date.ToString("U"));

The, emitted text is (I have an spanish language installation):
“lunes, 01 de enero de 0001 3:00:00”

Why it starts at 3 hours, instead of 0? it is a bug?

Answer 1

Well unless you’ve got a time machine or DateTime is really buggy, that’s not the output of the code you posted, which uses DateTime.Now.

I suspect your code is really using DateTime.MinValue (or new DateTime()), and the reason that you’re seeing 3am is that (as per the documentation):

The pattern is the same as the “F” pattern. However, the DateTime value is automatically converted to UTC before it is formatted.

So I suspect you’re in a time zone where midnight on January 1st 0001 local time is 3am UTC. (DateTimeZone.MinValue has a “kind” of Unspecified, so will be treated as local when asked to convert to UTC. DateTime is a bit of a mess around this area.)