Here is a quick Timer tutorial i posted on DR official forums:
Dragon Rising: Create a Timer for triggering Events
When you add a timer it will count from the start time down to 0 at which point the function onTimer_TIMERNAME(name) becomes usable.
Say you want to have Echelon1 moving from one location to another 5 minutes after your Player and his Fireteam entered triggerzone1:
function onEnter_triggerzone1(zoneName, UnitName)
OFP:addTimer("timer1", 300000) -- 300000ms = 5mins
hours, minutes, seconds = OFP: convertTimeToHMS(OFP:getTimer("timer1"));
OFP:displaySystemMessage("The time: " .. hours .. ":" .. minutes .. ":" .. seconds);
In the above the timer "timer1" is created when anyone enters triggerzone1, the timer is then display as in "HH:MM:SS" once only
(i dont know how to have it permanent and decreasing yet)
Note: the disableEvent is so that the Timer isnt created each time someone steps out of the triggerzone (it removes the trigger essentially)
OFP:move("Echelon1", "waypoint", "ADDTOFRONT")
This last bit will spawn and move the Echelon1 to the waypoint when the timer is up.
You could also use the timer to end a mission: