Spectre (2015 film):

A sequel to Spectre will begin development in spring 2016. Sam Mendes has stated he will not return to direct the next 007 film. Christoph Waltz has signed on for two more films in the series, but his return depends on whether or not Craig will again portray Bond.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". When will the sequel to Spectre being development?
spring 2016.