There is no announced or confirmed game called “Fallout 7,” and therefore there is no release date for it.

The mainline Fallout series is only officially up to Fallout 4, plus the online title Fallout 76 and the earlier isometric games; Bethesda has only publicly discussed a future “Fallout 5,” which is planned to come after The Elder Scrolls VI. Any dates you might see online for later, hypothetical entries like a “Fallout 7” are just fan speculation, not information from the developer.