It seems that plotly.js does not recognize an ISO 8601 timestamp with a character other than a space separating the date and time, e.g.:
2016-10-14 18:04:52.142018000 works, but
2016-10-14T18:04:52.142018000 is not parsed as a timestamp.

Obviously the "T" can be replaced with a space, but it would be nice to support the output of many standard JSON serializes.