You can use the formula =(B2/86400)+DATE(1970,1,1) to convert a unix epoch time to a human readable date (or date time). In my case, I have the unix timestamp in microseconds so I’ve got to divide by 86400000. The value you get is a not-so-meaningful float … but that’s actually a date.
Select a date format to display the value as a date
Or chose a custom format and use something like “m/d/yyyy hh:mm” to display a date and time.