The production dates for "Sherlock" Season 4 have not yet been locked. The details are still being worked-out. It looks like it is wait and more wait scenario at the moment.

"We're literally in the middle of working out what we're doing and the dates we've got. It's a bit of a watch-this-space, I'm afraid," Sue Vertue, executive producer of "Sherlock," said to Vulture.

As reported previously, the delay in filming of "Sherlock" Season 4 is because of Martin Freeman and Benedict Cumberbatch's busy schedules. Mark Gatiss and Steven Moffat, co-writers of "Sherlock," had said that they have mapped out the entire Season 4 and Season 5 of "Sherlock."

Earlier at the Bafta TV ceremony, Gatiss confirmed that the team of "Sherlock" is "moving closer to agreeing dates."

"Benedict and Martin's schedule, Steven's schedule, my schedule, everybody's schedule -- it's like a jigsaw puzzle," Gatiss had said, as quoted by Den of Geek.

Meanwhile, there is suspense surrounding the special episode of "Sherlock" before the telecast of Season 4. It is Freeman who had hinted about the one-off special episode.

"Mark Gatiss may beat me up, but there is an idea for this one-off special that's such a good idea," Freeman had said on Alan Carr's Channel 4 chat show, as quoted by Huffington Post.

He had called the one-off episode a "mouth-watering idea."

Moffat and Gattis, however, refuse to confirm that they are planning a one-off, special episode. Moffat said to Vulture, "It's all going in the right direction. There's nothing to worry about. Everyone's very willing to make it work. I'm sorry -- that's all you're getting for now."

When asked about the special episode, Gatiss had said, "there was talk amongst people who have nothing to do with "Sherlock," I'm afraid."

It was recently announced that "Sherlock" Season 3 will now be available on Netflix. In addition to the three episodes of the season, Netflix will also make available 'Sherlock Uncovered' as well as 'Unlocking Sherlock'.

'Sherlock Uncovered' is a set of three half-hour making-of specials following each episode, while Unlocking Sherlock is a one-hour behind-the-scenes feature about the making of the series, according to Vulture.