Black Friday 2013 is just three weeks away, and retailers are unveiling deals.

This year, many are starting their big sales a little before the day itself, which happens to fall on November 29.

Why the rush?

There are six less shopping days between Thanksgiving and Christmas this year. It’s just the way the calendar falls, but when it happens, retailers worry that it might translate to decreased holiday spending.

And, as retail analyst Candace Corlett puts it, “There’s a limited number of holiday gift dollars out there, and whoever gets them first, wins.” So when one retailer decides to start sales early, the others follow suit, unwilling to risk losing out on that fixed amount of consumer spending.

Retail giant and trendsetter Wal-Mart hasn’t unveiled its Black Friday deals, but it dipped its toes into holiday advertising when it published its 2013 Holiday Top Toy List in September. Then, on November 1, it announced Early Bird Online Specials, offering deep discounts on a range of electronics.

Got a big wish list? Get a jump on Christmas shopping with Early Bird Online Specials now. http://t.co/kjwSBtxa3H\

— Walmart (@Walmart) November 1, 2013

Wal-Mart wasn’t the only retailer to offer early bird discounts:

Save early. Save big! Shop our Holiday Kickoff 2-day sale with #deals on tablets, smartphones, laptops, HDTVs & more http://t.co/JwGdkxpX1U

— Best Buy Deals (@BestBuy_Deals) November 1, 2013

Amazon jumped in on the action with its Countdown to Black Friday Deals Week.

PetSmart will offer a three day pre-sale starting Monday, November 25 for both in-store and online shoppers.

Many retailers are opening for Black Friday shopping on Thanksgiving Day this year. Kohl’s, JC Penney, Macy’s, Sears, Target and Toys R Us are among those who have jumped on the bandwagon.

[BREAKING] Target Black Friday 2013 Sale Starts on Thanksgiving Day… http://t.co/g3ElTZydpK #BlackFriday #Target

— Black Friday (@blackfriday_fm) October 22, 2013

Kmart sparked controversy when it announced that its stores would be open from 6am on Thanksgiving morning until 11pm on Friday night. Dissenters have been particularly vocal on the company’s Facebook page, prompting the retailer’s social media team to reply that “We understand many associates want to spend time with their families during the holiday. With this in mind Kmart stores do their very best to staff with seasonal associates and those who are needed to work holidays.”

If Twitter is any indication, shoppers are already getting in the mood for Black Friday and holiday shopping:

Black Friday is all that's on my mind

— Dailee Helfrich (@daileehelfrich) November 8, 2013

i'm ready for Black Friday already!

— Lil Chris (@ImChrisSoles) November 8, 2013

saving up for black friday.

— Jaz (@jazziwoo_) November 8, 2013

The only reason why I like November is because Black Friday. I'm that girl that will kidnap your first born for a 75% off sweater.

— Kendall (@Kendallkampen) November 8, 2013

Im gunna blow so much money on Black Friday and cyber Monday

— Alexa Tysowski (@alexatysowski) November 8, 2013

Can't wait for Black Friday~~ #Deals #victoriasecret #epicsales

— Sophia Lau (@SoapEEA) November 8, 2013

Image via Facebook