Display time of object

[admin]

You will need two scripts for this.
1. Event script mapped to control or status object if the load:

Code:

value = event.getvalue()
key = 'ontime'
out = '32/1/5'

if value then
  if not storage.get(key) then
    storage.set(key, os.time())
    grp.update(out, '0m')
  end
else
  storage.delete(key)
  grp.update(out, '')
end

2. Scheduled script that runs every minute:

Code:

key = 'ontime'
out = '32/1/5'

time = storage.get(key)
if time then
  delta = os.time() - time
  minutes = math.floor(delta / 60)
  
  hours = math.floor(minutes / 60)
  minutes = minutes % 60

  if hours > 0 then
    res = hours .. 'h '
  else
    res = ''
  end
  
  res = res .. minutes .. 'm'
  grp.update(out, res)
end

32/1/5 is the object that shows the load ON time, set data type to 250 byte string. If you need multiple status outputs then use a unique storage key for each load (ontime in this example).