Static methods in java interface

As far as I know you cannot declare static methods in interface body. However, accidentally I found peculiar piece of code on http://docs.oracle.com/ site. Here is the link Namelly ``` public interface TimeClient { void setTime(int hour, int minute, int second); void setDate(int day, int month, int year); void setDateAndTime(int day, int month, int year, int hour, int minute, int second); LocalDateTime getLocalDateTime(); static ZoneId getZoneId (String zoneString) { try { return ZoneId.of(zoneString); } catch (DateTimeException e) { System.err.println("Invalid time zone: " + zoneString + "; using default time zone instead."); return ZoneId.systemDefault(); } } default ZonedDateTime getZonedDateTime(String zoneString) { return ZonedDateTime.of(getLocalDateTime(), getZoneId(zoneString)); } } ``` this `interface` has a `static` method `getZoneId` I am lost... could anyone explain please