Image 1
The standard command
/tempop <nick>
Link to image: http://dev.bukkit.org/media/images/59/443/2013-07-13_09.04.12.png
Player timed OP got the time
/tempop <nick> <czas>
Link to image: http://dev.bukkit.org/media/images/59/444/2013-07-13_09.05.00.png
The time has passed your OP and the global message
Link to image: http://dev.bukkit.org/media/images/59/445/2013-07-13_09.05.11.png