The USPS has posted the deadline dates for those planning to ship in time for holidays. many people can't make it to be with everyone for the holiday season so they end up shipping their gifts. The post office wants to make sure they can get your gift to its destination in time for Christmas morning so they have posted the deadlines well in advance of the rush.

Domestic USPS Mail-By Dates to assure delivery by December 24th

 First-Class Mail Dec 19
 Priority Mail Dec 20
 Priority Mail Express Dec 22

International shipping for the holidays, please use these Mail-By Dates

 International Mail Addressed To First-Class International Priority Mail International Priority Mail Express International
 Africa Nov 30 Nov 30 Dec  7
 Asia/Pacific Rim Dec  7 Dec  7 Dec 14
 Australia/New Zealand Dec  7 Dec  7 Dec 14
 Canada Dec  7 Dec  9 Dec 16
 Caribbean Dec  7 Dec  9 Dec 14
 Central & South America Nov 30 Nov 30 Dec   9
 Mexico Dec  7 Dec  7 Dec 14
 Europe Dec  7 Dec  9 Dec 14
 Middle East Dec  7 Dec  9 Dec 14

Happy Holidays and Happy Shipping!