You really shouldn't shower more than 2 times per day unless you're really dirty and need to shower off to clean off the dirt and grime.
Showering more than 2 times per day can cause your skin to dry out because of the loss of oils that are essential to your skin.
I shower at most 2 times per day to stay clean because I shower once before work in the morning and then again at night before bed.
I will however shower again throughout the day if I really need to.