free days

Recently I was free at work. I am a product marketing engineer. One of my job is to visit customers with a salesman to promote our products. My boss hopes we can visit customers every afternoon. Thus we can get more orders to increase our sales. I have stayed at the office for two days, but one of my colleagues who came to our department, one year later than me, always visit customers.
I like my job and I want to work hard, but I have no mood to do anything.