The John Lewis Christmas advert has for years signalled the coming of the most wonderful time of the year. No wonder Brits eagerly anticipate the retailer's commercial every holiday season.

With a new teaser having just popped up online, it's only a matter of time before the much-awaited ad presents itself to the excited viewers.

Before that, let's do a quick recap of what we know about this year's festive offering so far.

What does the teaser tell us about the John Lewis Christmas advert 2017?

The Twitter account "@UnderTheBed2017" posted a four-second clip on 6 November encouraging followers to Tweet using the hashtag "#UnderTheBed". The footage is believed to be a teaser for this year's John Lewis Christmas advert.

It was the font that gave away the secret, as it is the same one used by the department store.

In a short time, the account has garnered 5335 followers, even though it hasn't posted anything other than the teaser.

When will the John Lewis Christmas advert 2017 air?

Even though the scheduled date for the release hasn't been confirmed, the new online teaser means that the day isn't too far.

Last year, John Lewis put up a similar ten-seconds clip on Twitter on 7 November. The full-length advert was then aired on 10 November. An identical timeline can be expected for this year as well, which means this Friday, 10 November, seems like the most likely date.

What is the theme of the John Lewis Christmas advert 2017?

Again, not much is known about the theme of this year's advert. However, a few guesses can be made from the new Twitter teaser.

Rumours about this year's ad featuring a huggable monster like Gruffalo have already got everyone quite excited. The clip almost confirms this by showing a grey-eyed creature hiding in the dark

OK! magazine reported: "This year the John Lewis advert will revolve around a big cuddly monster. If you can imagine a cross between the Gruffalo and a huge, cute teddy bear, that's the angle they've gone for. Filming for the advert wrapped a couple of months ago but they've been doing a lot of post-production to get the special effects just right. Families are going to love the finished product, it's a really emotional advert with a lovely ending."

Who will perform the John Lewis Christmas advert 2017 song?

Apart from the theme itself, it's the heartwarming tunes that have put the perfect finishing touches to each John Lewis ad.

The songs used in the campaigns have been covers in most cases. From Lily Allen's version of Keane's Somewhere Only We Know to Ellie Goulding's cover of Elton Jonh's Your Song and Oasis' Half the World Away by little known Norwegian singer Aurora, the songs on these adverts have often done pretty well for themselves in the UK Singles chart.

This year many viewers and media outlets have speculated that John Lewis could pay a tribute to the late George Michael with a cover of the Wham! classic Last Christmas.

Which are some of the classic John Lewis adverts from the past?

The Long Wait: 2011

This was the year that John Lewis struck gold with their holiday commercial. The endearing ad features a young boy impatiently waiting for Christmas not because he wants presents for himself, but because he is dying to give his parents a gift.

For this ad, Slow Moving Millie covered The Smiths' Please, Please, Please Let Me Get What I Want.

The Journey: 2012

After the success of 2011's The Long Wait, the onus was on John Lewis to not disappoint viewers. What they did was exceed everyone's expectations with The Journey. The delightful tale is about a snowman who traverses the country braving every storm just so he can buy a warm scarf for his snow-girlfriend.

Gabrielle Aplin's cover of Frankie Goes to Hollywood's The Power of Love was ideal for the ad.

The Bear and the Hare: 2013

This is an adorable animated ad about friendship and innocence. As winter falls, the bear goes into hibernation leaving his friend the hare by himself. But the hare makes sure that he's not alone on Christmas by waking the bear up with a perfect gift — an alarm clock.

Lily Allen sang a version of Keane's Somewhere Only We Know for the advert.

Monty the Penguin: 2014

One of the most successful offerings from John Lewis, the ad tells the story of a young boy and his imaginary friend Monty who's looking for love. The boy then gifts Monty a female penguin for Christmas and everybody has a happy ending.

John Lennon's Real Love was covered by Tom Odell for this ad.

Man on the Moon: 2015

The 2015 John Lewis ad left the viewers in tears with a poignant portrayal of a young girl who catches sight of an old man sitting all alone on the moon while looking at her through a telescope.

Aurora performed a cover of Half the World Away by Oasis for this ad.