Time is measured in days, weeks and months. Weeks have seven days, and months have four weeks. Days represent game turns, where players may move their heroes on adventure map and manage their kingdoms. This does not happen simultaneously - rather, each player takes a turn, and then passes on play to the next player. Once all players have had their turn, the current day ends and the next day begins.
At the beginning of each day, mines and cities you control add to your resources. Resources represent gold and raw materials you may spend to improve your towns, recruit troops, and perform other actions. Town buildings that producing creatures do so on the first day of the week. Artifact Merchants replenish their stock on the first day of the month. The current date appears in the lower right corner of the Adventure Map screen.
The order in which players take their turns is as follows (assuming all colours are in the game and all players are human):
This is also the order in which the players appear in the tavern.
If there are computer players, they always have their turns after all human players.
Special Weeks and Months
Some weeks and months are special, increasing growth for a specific creature type (or, in the case of plague, decreasing for all), and potentially making new creatures appear on the map. See this page for more information.