val delay = 30.seconds              // equal to Duration.ofSeconds(30)
val longDelay = 2.5.minutes         // equal to Duration.ofSeconds(150)

val interval = 30L.days

val duration = 2.hours + 30.minutes
val period = 2.months + 14.days            
val duration = 1.hours - 1.minutes
val negativeDuration = -30.seconds

val fullDuration = 2.5.hours
val doubledDuration = 2.5.hours * 2
val halfDuration = 2.5.hours / 2

1.hours > 1.minutes
1000.nanos == 1.micros    

val (sec, nano) = 2.5.seconds
val (y, m, d) = 1.years + 2.months + 3.days

val lastHour = 1.hours.ago
val thisTimeTomorrow = 1.days.fromNow

val startTime = 30.seconds.fromNow
val stopTime = startTime + 1.minutes                                 // add Durations & Periods to dates & times

val thisYear: Year = 0.seconds.ago.year
val thisMonth: Month = 0.seconds.ago.month
val dayOfWeek: DayOfWeek = 0.seconds.ago.dayOfWeek
val currentTime: localTime = 0.seconds.ago.localTime

val startOfThisMonth = 0.seconds.ago.atStartOfThisMonth
val startOfNextMonth = 0.seconds.ago.atStartOfNextMonth
val endOfThisMonth = 0.seconds.ago.atEndOfThisMonth
val startOfThisYear = 0.seconds.ago.atStartOfThisYear
val startOfNextYear = 0.seconds.ago.atStartOfNextYear
val endOfThisYear = 0.seconds.ago.atEndOfThisYear

 (2010.asYear..2020.asYear).count() // should be equal to 11

 val inOfferPeriod = 0.seconds.ago in offer.start..offer.end
 
 for (d in date1..date2) {...}
 for (d in time1..time2 step 10 unit MINUTES) {...}
 for (d in dateTime1..dateTime2 unit DAYS) {...}

 (2010.asYear until 2020.asYear).count() // should be equal to 10
 for (d in date1 until date2) {...}
 for (d in time1 until time2 step 10 unit MINUTES) {...}
 for (d in dateTime1 until dateTime2 unit DAYS) {...}