Anything Harry Potter related has been popular this year

"We start planning for Christmas in October the year before," said company spokeswoman Neera Dhingra.

"At that time we will be thinking about it because our buyers need to visit the Far East to see samples and order stock from our suppliers.

"The stock tends to come in by ship so we need to make sure to order in plenty of time, then we get on with the current Christmas."

Retailers look set to enjoy a bumper Christmas this year, and the importance of sales in the run up to it can not be overestimated for most stores.

With Christmas out of the way Woolworths managers sit down in January to review what sold well and what did not.

They consider how well their management systems coped and what logistical lessons might need to be learned.

After reviewing their Christmas performance they will then look at more samples and order stock.

"Come April and our marketing team start to set out what we are going to do in terms of the store windows and Christmas adverts," said Ms Dhingra.

The Christmas rush is very important to retailers

"The first shipments of products from the Far East can also start arriving around then.

"In May, when I think most people's thoughts are on summer, we will be really getting stuck into our Christmas adverts.

"In June we will fill a store with Christmas stuff, to try out our signage and to see how everything is going to look.

"We used our Pinner store this year and I think that it thoroughly confused a few of our customers."

In August the television adverts - which this year featured Ant and Dec - were made at the London studios where James Bond movies are made.

Deliveries of Christmas stock to stores begin in October and then the TV adverts will start to be shown in November.

In the run up to Christmas an additional 5,000 staff will be recruited across the country.

Ms Dhingra said that in the final run up to Christmas staff from the firm's head office - even including directors - will help out in stores.

DVD films have been a major seller this year

"We really encourage that. We can get help to stores that need it that way, but it can also be very good for staff who are not usually in the stores.

"There is nothing like working in the stores to understand what is going on in the stores."

But no matter how good the planning is, there will always be things to catch the company out.

The surprise toy this year has been a candy floss maker - the manufacturer was also caught out, but has been able to get a few more out to stores.

Ms Dhingra said Harry Potter merchandise had been selling well, while perennial favourites were also popular.

The trick for big stores like Woolworths is trying to identify trends early.

Pogo sticks, which featured on this summer's Big Brother, were a surprise summer craze which Woolworths had to cope with.

"We were able to pogo sticks into stores quickly, but it shows the surprise element you cannot really ever completely plan for."

Ms Dhingra added: "It's a continuous cycle really. Different people will be working on Christmas all year round."