What is the meaning of this portion in Rails Datetime column?

Question

There is something in my view:

<%= debug @some_object %>
and the created_at field is shown as:
2012-01-30 03:16:37.996099000Z

So what is the meaning of the portion of .996099000Z???

I am using Rails 3.2 if it matters.

Thanks!

Answer 1

The final portion of the datetime is microseconds.