Weights are equal to the log of (1+the percent of days in the season that have passed). Therefore, the weight on the first day of the season is equal to log(1) and the weight on the day you rank the teams is equal to log(2). The weights on the days between take the shape of a log curve.
The weight of the game for the home/away/(or both if it's a neutral site) team is multiplied by the home/away/neutral weighting. If you think performance in home/away/neutral games is more indicative of a teams performance, make this weight larger.