The release date of 'Winds of Winter,' the next entry in George R.R. Martin's 'A Song of Ice and Fire' book series, is estimated for February, 2015. 

According to "Martinology," an analyst at website FiveThirtyEight, Martin's writing pace is about 300 words daily, just like JK Rowling, the author of Harry Potter. Based on this number, the analyst says Winds of Winter release date can be expected around February, 2015.

However, there is still no official announcement on the book's release date.

Jane Johnson, Martin's UK publisher, said at the start of this year that we won't see Winds of Winter in 2014. She added that she had no idea of the exact number of novels being planned for the series, saying only Martin knows the number of the books, something he is not disclosing.

Johnson told the Guardian, referring to the author's current writing stage, that stories of characters with multiple pathways that have yet to intersect.

George R.R. Martin is said to be taking his time when writing long books. The American novelist is also known for "A Game of Thrones," the first novel in A Song of Ice and Fire, on which the hit HBO series "Game of Thrones" is based.

Martin has earned a reputation for his slow writing pace, which has kept fans waiting and in a state of suspension.

Meanwhile, Anne Groell, the editor of Martin's books, previously mentioned the Winds of Winter release date, saying she has no knowledge when the sixth novel would come out. She said she had encouraged the novelist to write even when on trips, but adding that it was ultimately up to him.

As for the Winds of Winter plot, the author said it will feature even more heartbreaking twists, as well as betrayals, deaths and weddings.