This is going to be relevant in about chapter twenty. Please realize that the MC doesn't think twice about the days or months, so I will be adding a "translation" for the days and once months become an important thing, I will be adding the corresponding month after the Pokeworld's name for that month.
Sunday= Mewday
Monday = Giratiday
Tuesday = Palkiday
Wednesday = Dialday
Thursday = Grouday
Friday = Kyoday
Saturday = Arcday
Months are as follow:
January = Icesong
February = Psyrise
March = Flamestorm
April = Watermist
May = Grasswind
June = Groundcall
July = Aurawill
August = Flightrush
September = Thunderflash
October = Ghostwalk
November = Normal
December = Darknessfalls
PS (Dark types are actually known about, however the knowledge has been largely forgotten. Same with steel and fairy. Only the big shots really know at this point though obviously that will change. But you'll see some references in instances like this. ;D)