Is there high enough demand for nanoseconds in datetime and time instances?

How often nanosecond timestamps contain anything other than 0s or garbage in the last three digits?

In my experience, all people want to do with such timestamps is to convert them to something expressed in hours, minutes and seconds rather than just a huge number of seconds and back without loosing the value.

A timedelta is almost always a decent replacement for either datetime or time in those cases and sometimes it is even preferable because arithmetically it is closer to numbers.