/timercheck gives the setting for the timer called "check", it was broken in previous versions and listed all timers.
10/10/2003 - mIRC v6.11
49.Fixed /timerN without parameters listing all timers.
From the mIRC helpfile:
To see a list of active timers type /timers. To see the setting for timer1 type /timer1. To deactivate timer1 type /timer1 off. To deactivate all timers type /timers off. If you are activating a new timer you do not need to specify the timer number,