May 11 to be exact.
Ona stream held yesterday, Bushiroad has revealed various info regarding the anime of Cardfight!! Vanguard, besides the new teaser promo which you can see bellow (from minuten12:46 to 14:04):
Besides that, it got announced that the anime will continue onwards until 2020, and after that something new will come for the anime of Vanguard, no details were given, but it might be a new story that won´t feature Aichi or any of the characters already introduced.
Other info regarding the Trading Card Game were given, about the upcoming booster packs and the new imaginary gifts.
Via: Anime News Network