@Test
 public void monthsBetween() {
   assertThat(
       MONTHS.between(
           PlainTimestamp.of(2012, 1, 31, 12, 45), PlainTimestamp.of(2012, 2, 29, 12, 45)),
       is(0L));
   assertThat(
       MONTHS.between(
           PlainTimestamp.of(2012, 1, 31, 12, 45), PlainTimestamp.of(2012, 2, 29, 12, 44, 59)),
       is(0L));
   assertThat(
       MONTHS.between(
           PlainTimestamp.of(2012, 1, 29, 12, 45), PlainTimestamp.of(2012, 2, 29, 12, 45)),
       is(1L));
   assertThat(
       MONTHS.between(
           PlainTimestamp.of(2012, 1, 29, 12, 45), PlainTimestamp.of(2012, 2, 29, 12, 44, 59)),
       is(0L));
   assertThat(
       PlainTimestamp.of(2012, 1, 29, 12, 45)
           .until(PlainTimestamp.of(2012, 3, 28, 12, 44, 59), MONTHS.withCarryOver()),
       is(1L));
 }