/*
// returns crmUpdate field in Zulu time zone
if(doc['crmUpdate'].size() > 0) {
    doc['crmUpdate'].value.withZoneSameInstant(ZoneId.of('Z'))
} 
// returns created field in Zulu time zone
else if (doc['created'].size() > 0) {
    return doc['created'].value.withZoneSameInstant(ZoneId.of('Z'))
}
*/


if(doc['crmUpdate'].size() > 0) {
    long closingTime = ChronoUnit.DAYS.between(doc['created'].value.withZoneSameInstant(ZoneId.of('Z')), doc['crmUpdate'].value.withZoneSameInstant(ZoneId.of('Z')));
    closingTime
}