Convert to/from DateTime and LocalDate to BSONDateTime and ISODate

JodaBsonImplicitConverters.scala

import org.joda.time.{DateTime, DateTimeZone, LocalDate, LocalDateTime}
import play.api.libs.json._
import reactivemongo.play.json._

object JodaBsonImplicitConverters {
  // ### Automatic conversion of { DateTime, LocalDate } <-> BSONDateTime <-> ISODate ###

  implicit val dateTimeRead: Reads[DateTime] =
    (__ \ "$date").read[Long].map(new DateTime(_))

  implicit val dateTimeWrite: Writes[DateTime] =
    (dateTime: DateTime) => Json.obj("$date" -> dateTime.getMillis)

  implicit val localDateRead: Reads[LocalDate] =
    (__ \ "$date").read[Long].map { date => new LocalDate(date, DateTimeZone.UTC) }

  implicit val localDateWrite: Writes[LocalDate] =
    (localDate: LocalDate) =>
      Json.obj("$date" -> localDate.toDateTimeAtStartOfDay(DateTimeZone.UTC).getMillis)

  implicit val localDateTimeRead: Reads[LocalDateTime] =
    (__ \ "$date").read[Long].map { dateTime => new LocalDateTime(dateTime, DateTimeZone.UTC) }


  implicit val localDateTimeWrite: Writes[LocalDateTime] =
    (dateTime: LocalDateTime) =>
      Json.obj("$date" -> dateTime.toDateTime(DateTimeZone.UTC).getMillis)

  // ###################################################################################
}