/**
* Get the DateTimeValue corresponding to a given Julian instant
*
* @param instant the Julian instant: a decimal value whose integer part is the Julian day number
* multiplied by the number of seconds per day, and whose fractional part is the fraction of
* the second.
* @return the xs:dateTime value corresponding to the Julian instant. This will always be in
* timezone Z.
*/
public static DateTimeValue fromJulianInstant(BigDecimal instant) {
BigInteger julianSecond = instant.toBigInteger();
BigDecimal microseconds =
instant
.subtract(new BigDecimal(julianSecond))
.multiply(DecimalValue.BIG_DECIMAL_ONE_MILLION);
long js = julianSecond.longValue();
long jd = js / (24L * 60L * 60L);
DateValue date = DateValue.dateFromJulianDayNumber((int) jd);
js = js % (24L * 60L * 60L);
byte hour = (byte) (js / (60L * 60L));
js = js % (60L * 60L);
byte minute = (byte) (js / (60L));
js = js % (60L);
return new DateTimeValue(
date.getYear(),
date.getMonth(),
date.getDay(),
hour,
minute,
(byte) js,
microseconds.intValue(),
0);
}
