Time and season is implemented slightly differently here than elsewhere, but it breaks down simply enough.
For each 3 IRL months (4 week months) 1 RP year passes.
Ignoring the random 5 week month, each 1 IRL week is equal to 1 RP month.
For ever 1-2 IRL days it equals to roughly 1 week RP wise.
While we know this isn't exactly perfect, given the random 5 week month, and the fact that there are 7 days in a week, it helps us to keep a base of time, especially for the more active role-players who go from thread to thread in rapid succession.
Season is based upon each separate location, usually controlled by the Boss of that city, so please make sure to double check on how each location has their weather set up.