A mining company creates a set of rules to determine the best time to mine various minerals. Mining schedules offer a host of benefits as they allow miners to predict the value of goods to be received at a later date and choose when to sell.
A mining schedule does not necessarily need to set out which minerals are mined on what day of the month. Rather, it is simply a calendar that organizes mineral values by date so owners can choose when best to sell their goods. For example, some companies mine different minerals depending on market demand at the time of production. If coal is selling higher than iron ore right now, then they might produce more coal than steel-grade iron ore during this period instead of producing equal amounts each day.
Others might choose to mine lower-value goods during the summer season when people use less heating and more valuable goods during winter when cold temperatures drive up demand for energy resources. Depending on the industry you are in, there might be specific months of the year where your price is higher than other times.