The final Monday before Christmas is typically the busiest day of the year for the U.S. Post Service. That's tomorrow.
If you are one of those who are packing today in preparing of standing in line tomorrow, there are other options.
In San Francisco four post offices are open Sunday in hopes some of us will beat the rush:
You can also skip the trip to the post office and ship items on line using www.usps.com. It takes some effort, but you can print shipping labels and pay for postage at that url.
Monday, Dec. 20 is what the USPS calls the recommended deadline for sending cards you want to arrive in time for Christmas. Priority mail can still be sent Tuesday and express mail can be sent on Wednesday.
How busy is busy? The USPS says 800 million pieces of mail will come in Monday, which is 40 percent above average.