The United States Postal Service knew Monday would be the biggest day of the year before the day even started.

According to CBS, the USPS was expecting to handle shipments from more than six million customers while assisting another six million with online shopping.

"They can also do all their shipping online through 'click and ship.' You actually get a discount on your postage if you do that and you never have to go into a post office," USPS spokeswoman Eva Jackson said, according to CBS 8.

The San Diego Post Office, for example, expected to handle more than 1.8 million cards for the holiday and more than a quarter million packages, CBS said.

"Make sure you have a sturdy enough container," spokesman Richard Maher said. "You also want to make sure that your gift is cushioned, especially if it's fragile."

Although the USPS is dealing with the holiday rush before Christmas, they already got past the Black Friday marathon in November. With the Christmas holiday just over a week away, everyone will be scrambling to get their last-minute gifts and items while they're still on sale. We can expect things to slow down a bit more after the holiday, but this resurgence for the holidays is very much welcomed by the struggling USPS. The post office officials said that the overall amount of mail that has been shipping through the country went up 12 percent from last year.

The USPS website does have some helpful ways for shoppers to navigate the online shopping experience. For example, people can schedule a pickup while they are online and then the carrier can go and pick up your package for you. In addition, people can use shipping kiosks at post offices.

If you still need to make some purchases online before the holiday season comes to a close, you have plenty of time. As long as things are shipped by Express Mail by Dec. 23, people shouldn't experience as many difficulties with their packages being on time.