The IResponse::put_ExpiresAbsolute method sets the value of the ExpiresAbsolute property of the Response object.
HRESULT put_ExpiresAbsolute(
DATE dtExpires //date that contains the new ExpiresAbsolute value
);
If the user returns to the same page before the set date and time, the cached version is displayed. If a time is not specified, the page expires at midnight of that day. If a date is not specified, the page expires at the given time on the day that the script is run. If this property is set more than once on a page, the earliest expiration date or time is used. The date value sent in the expires header conforms to the RFC-1123 date format. The time value is converted to Greenwich Mean Time before an Expires header is sent.
Response Object, IResponse::put_Expires