GamePress
Shiny Meltan + Limited Shortened Box Cooldown
https://twitter.com/PokemonGoApp/status/1092891957368639489?s=09&
"Starting on February 5 at 1 p.m. PST, you have a chance to encounter Shiny Meltan when you use the Mystery Box! You can now also open the Mystery Box every three days for a limited time. Get your Mystery Box by connecting Pokémon GO with #PokemonLetsGo!"