Coffee or caffeine, in general, can be consumed between 10 AM and noon, or between 2 PM to 5 PM. It is not advisable to have coffee early in the morning since that is when the body produces a lot of cortisol. Cortisol helps reduce stress in the body.
Caffeine early in the morning starts to decrease the production of cortisol in the body. This creates a dependency of the body towards caffeine. It also increases the tolerance of caffeine in the body since it replaces the boost cortisol gives you.