The endpoint /api/geostreams/streams/:id returns time values in different formats:
"created": "2016-03-09T19:01:16Z"
"start_time": "2016-01-04T00:00:00-06:00"

In PostgresPlugin.scala
def getStream(id: String): Option[String] = {
var data = ""
val query = "SELECT row_to_json(t,true) As my_stream FROM " +
"(SELECT gid As id, name, to_char(created AT TIME ZONE 'UTC', 'YYYY-MM-DD\"T\"HH24:MI:SSZ') AS created, 'Feature' As type, metadata As properties, ST_AsGeoJson(1, geog, 15, 0)::json As geometry, sensor_id::text, start_time, end_time, params FROM streams WHERE gid=?) As t;"