In Catalonia, on Saturday, a record-breaking number of books are predicted to be sold as Catalans, like the English, celebrate their patron saint, St George (known here as Sant Jordi). A walk through any Catalan square will quickly land you in literary heaven: piles of books stacked high on tables with readers thumbing through the latest releases, in search of the perfect book for their loved one – and that’s not mentioning the six million roses for sale. With 1.5m books sold last year, grossing €20m, the Catalan publishing industry predicts an increase of up to 6%.

According to legend, Sant Jordi slayed a dragon to save his princess. From the pools of the beast’s blood grew a single red rose. “Traditionally, boys give girls a flower and girls give boys a book,” says editor-turned-Podemos politician Mar Garcia Puig. “Fortunately, we have evolved and now girls also receive a book.” Catalans have been exchanging books for roses for around 90 years, but after Unesco declared 23 April World Book Day in 1995, they began buying books on a mass scale.

The day “is an expression of the love Catalan people feel for culture,” says Puig, who for the first time in 10 years will not be escorting authors to different book signings. This year she will have to queue for a signature – something she’s rather looking forward to. “It is also a celebration of community,” she says, “as it is a day we all spend on the streets, walking around and meeting people”.

One of those who will be signing books is award-winning Catalan author Najat El Hachmi. “I have to be somewhere different every hour,” she tells me over coffee. “I enjoy the feeling of the day because it’s what I remember from when I was a little girl.” Najat emigrated with her parents to Catalonia from Morocco when she was just eight.

With book signings and rose-selling events scheduled to take place in 30 countries, the celebration is global. Albert Royo, head of Catalonia’s Diplomatic Council said: “We are trying to spread this festivity beyond our borders. Books and roses promote positive universal values: literacy, culture, peace, civility – and that is something we all share.”

• On 24 April, Borough Market hosts a Sant Jordi event (noon-4pm) with the help of Newham bookshop, enabling Londoners to enjoy their own literary St George’s Day