The key facts at the top count the earthquakes of magnitude 2.5 or greater that the U.S. Geological Survey listed in the past 24 hours and name the largest. The table lists up to 20 of them, largest first, with the place and the time in Eastern time.
Reading the list
USGS gives most locations as a distance and direction from a named place, so "26 km SW of" a town means the earthquake was about 26 kilometers southwest of it. Some locations are given only by region, such as an island group. The time is when the earthquake happened, converted to Eastern time.
When it updates
USGS updates its list of the past day's earthquakes every minute. This page reads that list every few hours and updates at the same address, with the time of the list shown in the key facts. For a California-only list that includes smaller earthquakes, see Was there an earthquake in California today?