SOA of .hk nameserver

Strange !   The serial of SOA of .hk nameservers is 2071434190 (Unix time) which converts to 22 August 2035 :

[warren@dnssec ~]# nslookup

> set type=soa

> hk.

Server:         202.81.252.116

Address:        202.81.252.116#53

Non-authoritative answer:

hk

        origin = NS1.HKIRC.NET.hk

        mail addr = HOSTMASTER.HKIRC.NET.hk

        serial = 2071434190

        refresh = 5400

        retry = 1800

        expire = 3600000

        minimum = 600

Is there a hidden fault ?