I can read a time from the file name of a Sentinel-2 image, but according to the user handbook of Sentinel-2, this time represents the time of ‘datatake’, I don’t know the exact starting point of ‘datatake’ and can’t calculate the approximate overpass time in my research area. Landsat series have very distinctive meta data for scene center time and ENVI can get this information correctly. By the way ,ENVI seems to mistakely read the ‘datatake’ time as the 'aquisition time‘。