ELISA ENGLISH's Blog 英語園地

Expiration: a coming to an end; termination; close: the expiration of a contract.

Expiry: an end or termination, as of life or a contract.  An expiration, especially of a contract or an agreement

Expiry 通常用於法律(合同)期限例如勞資協議到期，期貨合約到期。

Expiration 通常用於每日日常生活用語，例如駕駛執照到期日, 食品效期。

Expiration is more commonly used around day-to-day life stuff, such as expiration of food, expiration of your driver license.

While, expiry is more commonly used in legal (contract) terms such as the expiry of labor contract, the expiry of options/future contracts. 

Actually, a lot of the time, they are used interchangeably as you can see from the examples below. 實際上，很多時刻，他們可交換地使用。

On Medication -  

Most of what is known about drug expiration dates comes from a study conducted by the Food and Drug Administration at the request of the military.

http://www.health.harvard.edu/fhg/updates/update1103a.shtml

(From Harvard Medical School )

Warning given over expiry dates for drugs

http://www.irishhealth.com/?level=4&id=2625

(From Irish Health Co.)

http://www.stuartxchange.org/ExpirationDates.html

(From Dr. Susan Kashaf)

On Food –

Do Food Expiration Dates Really Matter?

http://www.webmd.com/food-recipes/guide/do-food-expiration-dates-matter

(From Web MD)

Managers on trial for altering food expiry dates

http://www.gulfnews.com/nation/Police_and_The_Court s/10206251.html

(From Gulf News)

On Contract -

Notice of any malfunction must be given to NHP prior to the expiration of this contract.

http://www.nationalhomeprotecti on.com/terms.php  

(From National Home Protection)

Tenancy contract becomes invalid after expiry of term

http://www.gulfnews.com/uaessentials/ask_the_law/housing_and_rent/10222338.html

(From Gulf News)