It depends on my work pensum and the level of concentration I need for my work, but usually I'm checking the site (at least hourly / every two hours) between
0700UTC - 1700UTC (core time)
and between (not every day)
2100UTC - 2300UTC
"Session length" between 2 to 10 minutes depending on how much time is at my disposal (I spend more time during my lunch break at ~ 1330UTC.)
Obviously, I don't maintain that rhythm when I'm not in the office or at home – which is maybe once or twice in two weeks.
Related answer here on Meta SF.
