This works for me:

on *:sockread:uptime:{
  if ($sockerr) { sockclose $sockname | halt }
  var %data
  sockread %data
  tokenize 32 %data
  if ($1 isnum) && ($2) { msg %channel %target has been online for $1 $2 $3 $4 }
  elseif (%data == The channel is not live. - Oh hey, you're using an API meant for Nightbot, not for whatever you're using. Maybe you'd want to try out the new Nightbot beta: msg %channel %target is currently not online.