FYI, Pyorbital is part of Pytroll (www.pytroll.org) which is a set of python libraries to read, calibrate and process meteorological and polar orbiting satellite images even at level 1.
Thank you, Sajid. But I wish there is a website like https://lpdaacaster.cr.usgs.gov/estimator/reference_info.php , where I could login in and inquiry VIIRS overpass time.