Review your time frame
Even though you might have confirmed the length of a sales meeting before the call, it's always good to do it again. You might not be aware that timing has changed for the customer. The following statement will set you straight: "I know we set aside an hour for today's meeting. I just want to make sure that still works for you."
Source: Sales consultant/author Barry Farber
Now, some people might be saying, "Why are you asking that again? You already got the time, and the customer might tell you that now he/she only has 30 minutes." The answer is courtesy. Also, if the customer has had a crazy day, his/her attention is not going to be focused on you. I've gone on calls with reps who dive right into their presentation, no nod to time, no ice breakers, and I'll watch the customer squirm in their chair and look at their watch as if wondering, "How long is this going to take?"
When you value the customer's time, it shows that you also value your own.