I am wondering that is there a table corresponds each snapshot to a time in Gyrs for TNG100. I saw we have a table on the website but I am wondering whether we have the same one in the output HDF5 file which I can use directly. Thank you!
The scale factor (or redshift) of each snapshot is available in Header['Time']. Then you could use the standard equations for the age of the universe at a given scale factor, or e.g. astropy.