Sherlock writer Steven Moffat has hinted that viewers should expect a wait of “two-and-a-half years” for the show to return.

Speaking at the Cannes Lions advertising festival, Moffat told The Guardian: “Had we done the conventional form of a TV series, which is to do runs of six or twelve, it would be over by now without doubt, it would be finished. Because [the cast] would never again commit that amount of time that regularly to a TV show; they just wouldn’t, why would they?”

He added: “But given the strange form of Sherlock, which is every two-and-a-half years we get together and we make three, means that it can go on for a very long time.”

Series 1 aired in July 2010. Series 2 aired in January 2012, following an 18-month gap. Series 3 aired in January 2014, following a two-year gap.

Moffat’s new “two-and-a-half years” comment would suggest that Series 4 will air approximately in the summer of 2016.

Sherlock co-creator Mark Gatiss recently revealed that he and Moffat had “moved significantly closer to getting a date in the diary for Series 4″.

> Here’s everything we know about Series 4 so far.

What are your hopes for Series 4? Let us know below…