From Board Game Geek:
Pay Day is played on a one-month calendar with 31 days. During the game, players will have to deal with various bills and expenses, but will also have the opportunity to make deals on property and earn money. At the end of each month, players are paid their salary (the same for each player) and must then pay off all outstanding bills, taking out a loan if necessary. Most money (or least debt) wins after a certain number of months decided by the players (3 months usually takes 30 minutes to finish).