Rule error for minusMinutes()

Setup, Configuration and Use Scripts & Rules
,
7

So that works:

rule "Open RollerShutters on sunrise and enough luminance"
when
    Item MultiOutLight_luminance received update
then
  val minus60 = new DateTime((Sunrise_Time.state as DateTimeType).calendar.timeInMillis - (60*60*1000))
  val plus60  = new DateTime((Sunrise_Time.state as DateTimeType).calendar.timeInMillis + (60*60*1000))
  if (Activate_Rule.state == ON) {
    logInfo("sunrise.rules","received update")
    if (minus60.isBefore(now) && plus60.isAfter(now) && MultiOutLight_luminance.state >= 20) {
      logInfo("sunrise.rules","Rollladen hochfahren")
      sendCommand(EG_Alle, UP)
    }
  }
end

but I get this validation error:

2018-02-24 10:47:21.701 [INFO ] [el.core.internal.ModelRepositoryImpl] - Validation issues found in configuration model 'sunrise-new.rules', using it anyway:
The method getCalendar() from the type DateTimeType is deprecated
The method getCalendar() from the type DateTimeType is deprecated
Item label and variables