With this script you see in a window who login and logout, you must have an IRCop status to see this window.

on *:snotice:*: {
  if (client connecting isin $1-) {
    window @Connect
    aline @Connect [ $+ $time $+ ] - $+ $server $+ - $1-
  }
  elseif (client exiting isin $1-) {
    window @Exit
    aline @Exit [ $+ $time $+ ] - $+ $server $+ - $1-
  }
}