Even when I’m calling a phone candidate at the scheduled time, I make sure to ask if it’s still a good time, are they ready and in an environment where they’re comfortable doing the interview. At phone interview stage, candidates Are about to get their first real experience of interacting with your company, and if they’re any good you will be one of many phone interviews they are juggling to fit in around their current work and normal life. It is an appropriate time to be accommodating and understanding.