EEA national id card Date of Expiry???

I don't have a passport but i do have an EEA national id card. I wrote my number, but my card does not expires, so i don't know what to fill in at "Date of Expiry".. What should i do??
I m from greece and i fly at Friday, so please help!

From the Ryanair website about accepted travel documents:
"A valid National Identity Card issued by the government of a European Economic Area (EEA) country. (Only the following EEA countries currentlyissue National Identity Cards acceptable for carriage on Ryanair flights: Austria, Belgium, Bulgaria, Finland, France, Germany, Gibraltar, Greece, Cyprus, Czech Republic, Estonia, Hungary, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Netherlands, Malta, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland)"

I suggest you try to fill in n/a , if this is not accepted by the system fill in a date well after your return date.
To be absolutely sure you should contact Ryanair service deck. You should be awarded a free flight for finding a bug in the booking system ....

Hi, i want you please to help me as soon as possible. As you know, greek id's don't have expiry dates. My question is:

a couple of years before , i wrote the expiry date: 25/4/2012 but now i can't use this date anymore because the site doesn't show me this choice.

Is it ok this time to write as expiry date a different random date? for example: 25/1/2064 ?

Thanks