Datetime comparison help

[DSTM (Neil)]

I have a DateTime item named LastVacuumDate with a saved value via jdbc persistence. I want to see if the time now is more than 24 hours after LastVacuumDate.

The rule would be something like below, but I can’t find any examples or work out the right syntax. Is anyone able to give me some pointers please?

rule "vacuum_walkies"
when
    Time cron "0 */20 * * * ?"
then 
  var DateTime TimeNow = now

   if (LastVacuumDate.state.plusHours(24) < TimeNow) {
	// more than 24 hours has passed, so do the vacuuming again
	VacuumMsg.postUpdate("the vacuum is going walkies...")
	// blah blah blah....
   }

(I want to do it in that way, because depending on some extra conditions [still to be added] the vacuum might wait for 48 hours instead of 24 hours)

[rlkoshak (Rich Koshak)]

@DSTM

(I want to do it in that way, because depending on some extra conditions [still to be added] the vacuum might wait for 48 hours instead of 24 hours)

So why not trigger the rule based on changes in those other conditions?

@DSTM

The rule would be something like below,

You need to cast the state to a DateTimeType and use the methods on now or the DateTimeType to do the comparison.

See

Type Conversions

Attention: This article is now also available on the openHAB 2 documentation page. If you want to add improvements or additions, please do so there. http://docs.openhab.org/configuration/rules-dsl.html#conversions Interacting with Items in rules A frequent operation in rules is to calculate other values from Item states or compare Item states against other values or perform other operations that are either responses to changes in item states or intended to change the item state. For a complete…

[DSTM (Neil)]

@rlkoshak

See …

Thanks. That was exactly the sort of documentation I was looking for, but couldn’t find.

[rlkoshak (Rich Koshak)]

It is in work and that article will be added to the docs shortly.