It's that time of year again.

Autumn is creeping into winter, and Christmas is just around the corner. And it's time to spend all your hard-earned savings on gifts and treats for loved ones. Yes, it's the most wonderful time of the year, but it's also expensive. So, you need to hit up Black Friday and save a few bucks.

The day after Thanksgiving in the US is when most major retailers agree to open up very early - often even during overnight hours - to offer sales and steep discounts. On that day, consumers can presumably get the most amount of goods for the least amount of money.

Here's everything you need to know about it.

Black Friday is an unofficial holiday that kicks off the intense Christmas shopping season in the US.

On Black Friday, most retailers open early and offer day-long or weeks-long sales, but as competition for customer dollars heats up, stores are opening up even earlier and staying open even longer. For years, it was common for retailers to open at 6 am EST, but this has been taken a new extreme in recent years, with several retailers now opening in the evening on Thanksgiving. 

In 2015, total spending over the four-day Thanksgiving weekend reached $50.9 billion, according to the National Retail Foundation. That was down 11 percent from $57.4 billion in 2013, and it marked the second year of sales declines.

Black Friday follows Thanksgiving Day in the US (the fourth Thursday of November). That means, in 2016, Black Friday is 25 November.

In recent years, some retailers such as Amazon have begun introducing retail Black Friday in the UK. Asda (a subsidiary of Walmart), very.co.uk, John Lewis, Argos, and other UK stores were among the many retailers that decided to partake. In 2015, Black Friday hit the £1 billion sales mark in the UK, and total sales over the weekend surpassed £3 billion.

The UK also has Boxing Day, the day following Christmas. It's also a famous sales day in the UK.

Check your favorite retailer's website now. Whether you plan to shop in person or online, there is a website for that retailer which will have some page detailing the best Black Friday deals they plan to offer and when. There will also be details on in-store or online-only sales and what hours they'll be available. It's tedious, but if you check every retailer now, you will find their deals.

To make it easier for you to find the best details from Amazon, Walmart, BestBuy, and other retailers that sell electronics, gadgets, devices, headsets, TVs, gaming consoles, phones, tablets, set-top boxes, headphones, video games, and what not, Pocket-lint published a guide of the best technology-related Black Friday and Cyber Monday deals. So make sure to check that.

Cyber Monday is the Monday after Thanksgiving in the US. It started as a day when online retailers lured online shoppers with sales. In recent years, Thanksgiving, Black Friday, and Cyber Monday have blended into a four-day weekend in which Christmas shoppers can look for deals through both physical stores and online stores.