Our bloom times are relative to the spring bulb flowering season. An Early selection will generally bloom before a Mid selection and a Mid selection before a Late selection.
We can't be more specific about bloom time because spring arrives at different times in different parts of the United States. An Early selection planted in Memphis, for example, may flower 4 weeks earlier than the same Early selection planted in Chicago.
To get an idea of when a given bulb will bloom in your area, think of a spring-blooming bulb you are familiar with. Let's say you remember that daffodils bloom around the end of March in your area. Since most daffodils are early bloomers, consider them to be your benchmark time for Early bulbs. A Mid selection will typically bloom about 14 days later, and a Late selection will bloom about 14 days after the Mid. As you might guess, a Very Early bulb will flower before an Early selection.
You can select from each bloom time to create an extended spring display.