Life moves quickly. It’s easy to get distracted. But that can be costly.

Miss an important financial date or deadline, and you could be on the hook for a penalty or lose out on a limited-time opportunity to save money.

Enter our money calendar series.

In this edition, we’ve rounded up the noteworthy money dates that are coming up in December. Take a look and mark your calendar with any dates that apply to you.

Dec. 2 — Cyber Monday

The Monday after Thanksgiving (Nov. 28 this year) and Black Friday (Nov. 29) is one of the biggest retail holidays of the year. So, be ready for the bombardment of sales — which will last for days in many cases. (Dec. 2 isn’t just Cyber Monday — it’s the official kickoff of Cyber Week.)

In the meantime, check out “The 6 Best Things to Buy in December — and 3 to Avoid” to find out what types of purchases to make in early December and which to postpone until after Christmas if not the new year.

Dec. 7 — Medicare open enrollment ends

The fall open enrollment period for Medicare — the federal health insurance program primarily reserved for folks age 65 and older — started Oct. 15 and ends Dec. 7.

Medicare recipients who have yet to do their open enrollment homework should check out our latest Medicare coverage and round up the following resources ASAP:

• Medicare.gov — particularly the Medicare Plan Finder feature
• 2020 “Medicare & You” handbook
• Evidence of Coverage document
• Plan Annual Notice of Change document

Dec. 9 — Green Monday

If you manage to miss both Black Friday and Cyber Week, know that you will likely have another chance to snag a deal on the second Monday of December, aka Green Monday.

This retail holiday was started by eBay in 2007 because the second Monday of December was historically the company’s best day of the year for sales.

Last year, big names like Target were among the retailers that “celebrated” Green Monday with sales.

Dec. 14 — Free Shipping Day

Another retail holiday, Free Shipping Day was started in 2008 and falls on Dec. 14 this year.

On that day, participating retailers big and small will offer free shipping on all orders, with no minimum purchase requirement and with delivery promised by Christmas Eve. Check FreeShippingDay.com when Dec. 14 nears for a list of participating retailers.

Dec. 15 — Obamacare open enrollment ends

The annual open enrollment period for Obamacare health insurance policies started Nov. 1 and ends Dec. 15.

If you buy coverage through one of the health insurance marketplaces created by the Affordable Care Act (ACA) of 2010, this period is your opportunity to enroll or re-enroll in a plan for 2020. (All 2019 plans will end on Dec. 31, regardless of enrollment date.)

If you need a 2020 plan but have yet to enroll or re-enroll in one, start by reviewing these resources from the federal government’s HealthCare.gov website:

• Open enrollment checklist
• “Quickly find your 2020 Marketplace costs” blog post
• “Ways to apply for 2020 health insurance” webpage
• “See plans & Prices” webpage

Dec. 26 — Day after Christmas

We’ve seen the day after Christmas become a retail holiday of its own in recent years, generating sales on more things than just holiday decorations.

So, keep an eye out. And again, check out “The 6 Best Things to Buy in December — and 3 to Avoid” to find out what types of purchases to postpone until after Christmas.

Dec. 31 — Last day old Medicare cards and numbers are valid

The federal government has issued new Medicare health insurance ID cards and numbers over the past couple of years. The change was designed to prevent identity fraud, as we detailed last year in “What You Must Know About the New Medicare Card You Will Get Soon.”

Old Medicare cards and numbers are only valid until Dec. 31, meaning folks on Medicare cannot use them to receive health care services after that. Instead, you must present your new card and number. So, make sure you have the new card handy before the new year arrives.

If you still have yet to receive a new card, Medicare advises that you:

1. Sign in to MyMedicare.gov to get your number or print your official card. Now that we’ve finished mailing new cards, your new number will appear in MyMedicare.gov.
2. Call 1-800-MEDICARE (1-800-633-4227). TTY users can call 1-877-486-2048. There may be something that needs to be corrected, like your mailing address.

Dec. 31 — 5 tax deadlines

April 15 might be the most notorious tax deadline, but Dec. 31 brings us more federal income tax deadlines than perhaps any other day of the year.

For example, Dec. 31 is the deadline to do the following for tax year 2019:

• Make contributions to most employer-sponsored retirement accounts.
• Make required minimum distributions (RMDs) — for folks who were 70½ or older going into 2019. (Those who turned 70½ during 2019 have until April 1.)
• Withdraw excess contributions to individual retirement accounts (IRAs).
• Spend money in flexible spending accounts (FSAs), generally.
• Make charitable contributions. This applies only to taxpayers who itemize their tax deductions, however.