E-mini S&P 500 time frame

where it says Opening and Closing price in the Daily Notes for E-mini S&P 500
what is the opening time and closing time?
In other world what is the time frame utilized ?

THank you

For that contract it would be: 5:00 PM - 4:00 PM (Sun-Fri) CST
It settles at 3:00 PM (again CST)