In this URL Gant Chart displays a demo of a chart, listing names and displaying end times of tasks.
It happens that even searching, reading the documentation, changing format, period, among other options, I could not display the seconds along with the hour and minute, nor did the script take into account minutes and seconds in calculating tasks.
In the current demo, if any employee starts 12hs activity, and lasts 3 hours, he displays the 12-15 interval on the chart. But if the activity starts 12 hours and lasts 1 hour, 20 minutes and 33 seconds, it does not display in so many details.