2 hour timer

[benanderson_475]

I need to switch the exterior lights off for the building 2 hours after store closes which is set by preset schedule time and switches group 2/2/2,

Currently i have an event script on 2/2/2(trigger from schedule) storing the os.time() at the scheduled time, then a resident script set to 60s checking the difference between 
the stored value and the current to see if time has expired like

Code:

schedule_off = grp.getvalue('2/2/2')


if not schedule_off  then -- (2/2/2 = false )
if os.time() - storage.get('store close') >=  60*120 then

--switch lights off
end
end

i only need this script to run while the 2 hr period is active then it can stop running until next time the schedule runs, where as at the moment it runs always when the schedule has triggered it until the next scheduled time switches it again. 

is there a way to receive the scheduled off time for the schedule (from the schedular) and add 2 hours to this then execute the off command after the 2 hour period?
like having an offset value for a specific timed schedule, the same as in sunrise/sunset + or - 1 hour etc? 


is there a better way to do it and what is best?