About how long until Sherlock Holmes gets released for US?

He's the future servant I'm looking forward to the most, and I'm starting to save up quartz so I can have a large stockpile to try and get him. But depending on how long of a wait, I may spend some rolling for other servants in the meantime.

Is there any kind of estimation of when he'll be added? In JP he was released last year in July/August I think, will it be around the same time this year for the US version?