How to convert DateTime-Item (DateTimeType) to DateTime in rules

[Mjohannessen (Mark Johannessen)]

Thanks - I’m on OH 2.5.3 so this was helpful:

DateTime Conversion (openHAB 2.x)

Because openHAB 3.x rules now use Java Time API instead of Jodatime, there is a new DateTime Conversion thread for openHAB 3.x. Overview In openHab 2.x there are different ways to handle Date/Time values. DateTimeType A DateTime Item carries a DateTimeType. Joda DateTime By default openHAB 2.x-Rules use a Joda DateTime class to represent time, most notably now. Epoch The lowest common denominator when working with time is to get at the epoc value. Epoc is the number of milliseconds …

Using that, these work to get hours:

rule "testing"
when
    System started
then
    logInfo("rules", "Testing")

    // now is Joda DateTime class
    var hours = now.getHourOfDay()
    logInfo("rules", hours.toString())

    // OfficeMotion_time is a DateTime object so convert to Joda
    val jodaValue = new DateTime((OfficeMotion_time.state as DateTimeType).zonedDateTime.toInstant.toEpochMilli)
    var hours_2 = jodaValue.getHourOfDay()
    logInfo("rules", hours_2.toString())

end