This is something I use, to make something happen at the top of every hour. I'm not sure it's the best way to go about it but here is what I do:
Code:
| Figure out how many seconds until the next O'clock
/varset HourTimer ${Math.Calc[3600-((${Time.Minute}*60)+${Time.Second})]}s
| Timer Event Section
Sub Event_Timer(tmrName)
/if (${tmrName.Equal["HourTimer"]}) {
| Reset the timer for another hour
/varset HourTimer 3600s
/echo Do some event at the top of the hour here
}