Help example on simple light controll, lux

[Joep]

Try this

Code:

lux = grp.getvalue('1/1/1') setpoint = grp.getvalue('1/1/2') output = '1/1/3' hysteresis = 20 --in %   Limit_ON = setpoint - ((hysteresis/100)*setpoint) Limit_OFF = setpoint + ((hysteresis/100)*setpoint)   if (lux >= Limit_OFF) then    grp.checkwrite(output, false) elseif  (lux <= Limit_ON) then      grp.checkwrite(output, true) end

I would like to replace the hysteresis from this script for a time period. So let's say i want an hysteresis for 30 minutes how can this be done?