Letter carrier Kevin Pownall delivers mail in Philadelphia. (Matt Rourke/AP)

Today marks the start of a busy stretch of days for the U.S. Postal Service, with Friday expected to be the busiest mailing day of the year for holiday packages, according to postal officials.

Most of those holiday packages are slated to arrive at final destinations Monday, while Tuesday is considered the busiest day to mail holiday cards. (For the record, The Eye — thanks to the always diligent Mrs. Eye — is well ahead of schedule.)

Colorful ornaments will be the next issue of holiday stamps. (USPS)

And then there are stamps: The Postal Service produces about 2.5 billion stamps every holiday season and said it sells on average two contemporary holiday stamps for every one traditional/religious stamp.

In order to guarantee the delivery of cards and packages in time for Christmas, customers should put packages in the mail by today and cards in the mail by next Tuesday. Priority Mail customers have until next Wednesday to guarantee delivery by Christmas; Express Mail customers have until next Thursday.

Follow Ed O’Keefe on Twitter: @edatpost

Further reading:

Postal Service delays closing post offices

Postal Service and unions extend contract talks

For more, visit PostPolitics and The Fed Page.