public static ZonedDateTime zonedDateTimeOf(final Instant time) {
        return Optional.ofNullable(time).map(instant -> instant.atZone(ZoneOffset.UTC)).orElse(null);
    }
Zoned date time.

@param time the time
@return the zoned date time
core/cas-server-core-util-api/src/main/java/org/apereo/cas/util/DateTimeUtils.java