Time is running out to ship your gifts and order them for guaranteed delivery by Christmas Eve.

Monday is the deadline for FedEx's ground and home delivery, while Tuesday is the deadline for UPS's most affordable delivery option, UPS 3 Day Select. The deadline for free shipping on Amazon orders also is Tuesday.

The Postal Service's deadline for its priority and first-class mail is more generous and packages need to be mailed out on Thursday. 

In a statement, USPS said Dec. 17 was anticipated to be its "busiest day online with more than 8 million consumers predicted to visit usps.com for help shipping that special holiday gift."  

The week through Dec. 23 also is expected to be the service's busiest week for mailing, shipping and delivery. It expects to process and deliver nearly 3 billion pieces of First-Class Mail, including greeting cards.

All three major carriers, Amazon and many retailers also offer last-minute options. 

To help them make sure your gifts get to their final destination on time – and save a little money – there are a few key shipping deadlines to pay attention to.

More: Amazon's extending free shipping and same-day delivery for last-minute shoppers

More: Want your gifts by Christmas? Order by these dates

More: 50 amazing gifts for every type of person and budget

These are the three major carriers' recommended send-by dates for expected delivery by Dec. 25:

U.S. Postal Service

Dec. 18: APO/FPO/DPO (except ZIP code 093) through Priority Mail Express

Dec. 20: First Class

Dec. 20: Priority Mail

Dec. 22: Priority Mail Express

FedEx

Find rates and transit times at www.fedex.com.

Dec. 17: Ground and home delivery

Dec. 19: Express Saver

Dec. 20: Two-day options

Dec. 21: Overnight options

Dec. 25: FedEx SameDay, FedEx SameDay City Direct and City Priority

United Parcel Service

Calculate time and cost at www.ups.com.

Dec. 18: UPS 3 Day Select

Dec. 20: 2nd Day Air

Dec. 21: Next Day Air

Dec. 22: UPS On-Call Pickup for UPS Next Day Air

More: 'A Christmas Story': 35 reasons why we still love the holiday classic, 35 years later

More: Here's what happens to unsold Christmas trees

More: Massive Christmas light display flashes in sync with 'Baby Shark' song

From: https://www.usatoday.com/story/money/2018/12/17/ups-christmas-deadline-shipping-fedex-usps-last-day/2334813002/