zoned.scala

import shapeless._
import org.joda.time.{DateTime, DateTimeZone}
 
sealed abstract class Zoned[Z <: DateTimeZone] { 
    def dt: DateTime 
    override def toString: String = dt.toString
}
object Zoned {
    private case class zonedImpl[Z <: DateTimeZone](dt: DateTime) extends Zoned[Z]
    def apply[Z <: DateTimeZone](dt: DateTime)(implicit w: Witness.Aux[Z]): Option[Zoned[Z]] = {
        val zone = w.value
        if (dt.getZone == zone) Some(zonedImpl(dt))
        else None
    }
}
 
// USAGE
scala> import DateTimeZone.UTC
import DateTimeZone.UTC
 
scala> val PacificTime = DateTimeZone.forID("US/Pacific")
PacificTime: org.joda.time.DateTimeZone = America/Los_Angeles
 
scala> Zoned[PacificTime.type](new DateTime())
res0: Option[Zoned[PacificTime.type]] = Some(2015-12-30T14:28:35.921-08:00)
 
scala> Zoned[UTC.type](new DateTime())
res1: Option[Zoned[org.joda.time.DateTimeZone.UTC.type]] = None
 
scala> Zoned[UTC.type](new DateTime().withZone(UTC))
res2: Option[Zoned[org.joda.time.DateTimeZone.UTC.type]] = Some(2015-12-30T22:28:52.776Z)