Do all the alpha-kids live in different times on earth, even Roxy and Dirk? Is it the same for the beta-kids? And if, in which order do they live?

Beta kids all live at the same time landing in 1995-96 making them 13 when Homestuck started, Jane and Jake would have landed in the same timeframe post scratch, Dirk and Roxy being from 413 years in the future of course landed in 2409.