There's only one week until Christmas, and it's crunch time for the US Postal Service.

Monday is the start of the busiest week for workers there. 

They're expecting to deliver more than 200 million packages.

Officials say the spike will really kick in around Wednesday.

But, do not worry: people still have time to get those packages shipped and delivered on time.

"It's a little different this year with Christmas being Monday; everybody has to try to aim more for a Saturday delivery. Remember this week, even though it's a big robust one, is kind of shorter for your mailing purposes," said Maureen Marion, Northeast USPS communications manager.

The postal service predicts about 6 million packages will be delivered on Sunday, Christmas Eve.