Relation between "Registrar Registration Expiration Date" and the actual expiry
You hit probably one of the worst corner case of domain names, one that is often poorly explained everywhere and that causes a lot of problems.
The following applies to gTLDs (some ccTLDs may work the same way, some completely differently): they work in an auto-renewal mode. This means that, at the registry level, a domain really never expires, it gets renewed automatically, except if the registrar decides otherwise.
Here is how it happens:
- at domain expiration date, typically on the day but not necessarily on the exact same time, the registry will auto-renew the domain name, meaning that its expiration date will get changed to be one year further in the future
- then a counter starts, of typically 45 days (but registries can choose another length) - called the auto-renew grace period, where the registrar can act, that is if the registrar do not wish the domain name to be renewed it has to act during this period and ask the registry to delete the domain name (he will then get refunded by the registry because otherwise obviously the registry will bill the registrar for the auto-renewing). If the registrar does nothing, passed the delay, the domain name is "definitively" renewed.
The above explains why you may see two dates: during the typical 45 days delay, when the registry already renewed the domain name, its expiration date will be 1 year in the future, where the date at the registrar level will show the domain as expired, until you really ask (and pay) the registrar to really renew it. Note also that the registrar is not forced to give you the full 45 days delay to think if you want to renew it or not: it could as well decide to delete the domain name if, for example you still have not paid 30 days after expiration; this is only his own choice but should be reflected in its conditions and contracts that you should read at some point (again, in gTLDs, ICANN regulations require registrars to disclose their policy about what happens for "expired" domain names; ICANN policies also requires registrars to send notification in advance to warn about the coming expiration).
So that is the explanation of why you have two dates, handled at two different levels, and the discrepancy between them. This creates a lot of questions in fact.
For your specific case, I would still be worried, because if you paid your registrar to renew the domain name, the registrar expiration date should have been changed. You should investigate the issue. However, it may also be a glitch in the system as normally domain names that have been auto-renewed and still in their grace period of 45 days do show autoRenew period in the registry whois output in the statuses fields (have a look at the URL given in the above whois output, on ICANN website).