public static Period createYearMonthDayPeriod(final Integer year, final Integer month, final Integer day) {
        final ZonedDateTime dateTime = LocalDate.of(year, month, day).atStartOfDay(UTC);
        final long from = dateTime.toInstant().toEpochMilli();
        final long to = dateTime.plusDays(1).toInstant().toEpochMilli();
        return new Period(from, to);
    }
Create a day period.

@param year  e.g. 2001
@param month e.g. 01=jan
@param day   e.g. 31
stroom-util/src/main/java/stroom/util/PeriodUtil.java