timer counter

Hej pomożecie nie widzę błędu a nie działa jak powinno. Założenie, że zlicza mi czas działania switch Piec po włączeniu na ON a widzę że się zmienia jak przełącznik jest na oFF.

var long LastUpdate2 = 0
rule "Piec time calculation"
when
Item Piec received update
then
var long currentTime2 = now.millis

if (LastUpdate2 != 0) {
var long timeElapsed = currentTime - LastUpdate2
if (timeElapsed > 0) {
var Number timeperiod = timeElapsed / 1000 //min
postUpdate(TotalPiecTime, TotalPiecTime.state as DecimalType + timeperiod)
postUpdate(DailyPiecTime, DailyPiecTime.state as DecimalType + timeperiod)
}
}

LastUpdate2 = currentTime
end

*.items

Number TotalPiecTime "total time [%.0f min]"
Number DailyPiecTime "todays time [%.0f min]"

log:

2018-01-12 14:41:27.827 [vent.ItemStateChangedEvent] - Piec changed from OFF to ON
2018-01-12 14:41:27.861 [vent.ItemStateChangedEvent] - TotalPiecTime changed from 37 to 38
2018-01-12 14:41:27.868 [vent.ItemStateChangedEvent] - DailyPiecTime changed from 37 to 38
2018-01-12 14:42:28.965 [vent.ItemStateChangedEvent] - Piec changed from ON to OFF
2018-01-12 14:42:28.998 [vent.ItemStateChangedEvent] - TotalPiecTime changed from 38 to 39
2018-01-12 14:42:29.003 [vent.ItemStateChangedEvent] - DailyPiecTime changed from 38 to 39
2018-01-12 14:43:30.349 [vent.ItemStateChangedEvent] - TotalPiecTime changed from 39 to 40
2018-01-12 14:43:30.351 [vent.ItemStateChangedEvent] - DailyPiecTime changed from 39 to 40
2018-01-12 14:44:31.313 [vent.ItemStateChangedEvent] - TotalPiecTime changed from 40 to 41
2018-01-12 14:44:31.325 [vent.ItemStateChangedEvent] - DailyPiecTime changed from 40 to 41
2018-01-12 14:46:33.781 [vent.ItemStateChangedEvent] - TotalPiecTime changed from 41 to 43
2018-01-12 14:46:33.790 [vent.ItemStateChangedEvent] - DailyPiecTime changed from 41 to 43