Twenty-three Oahu post offices will be open for extended hours after Dec. 13 to move the anticipated heavy volume of holiday cards and gifts. The Airport and Ala Moana branches will also be open on Sunday, Dec. 14.

The Postal Service recommends that letters and gifts to military service members at APO and FPO addresses be sent no later than Dec. 8 by first class or priority mail or Dec. 15 by express mail.

Recommended mailing dates reflect the best chance of reaching the destination by Christmas. They are not deadlines, according to a postal service release. The agency recommends sending off packages by the following dates:

» Monday - first class and priority mail to Africa and Central America, or Dec. 10 express mail

» Dec. 8 - other international destinations; Dec. 15 express

» Dec. 11 - American Samoa; Dec. 17 express

» Dec. 15 - Guam and Saipan; Dec. 17 express

» Dec. 17 - U.S. mainland; Dec. 19 express

» Dec. 22 - Hawaii; Dec. 23 express

Authorities suggest that customers use flat-rate boxes, including a new large size, available free at post offices.

Customers can avoid lines by using the self-service Automated Postal Centers outside 18 post offices to buy stamps, print labels and pay postage for packages and conduct other common transactions.

For information on hours, free package pickup and other questions, call (800) 275-8777 or see the Web page www.USPS.com.