From the Radio Times web-page (
https://www.radiotimes.com/news/on-d...ime-video-bbc/)
"All six hour-long episodes of the series are set to be released on Amazon Prime Video globally on Friday 31st May 2019.
According to Gaiman it will then air weekly on BBC2 in the UK around six months later (as it is a co-production between Amazon and the BBC). That’s expected to be followed by terrestrial TV broadcasts around the world."