I'm a shitty person but I schedule my phone screens either early in the morning before work (I come in at 10am), or during gaps in my work schedule, and I'll go to the parking lot and sit in my car for the phone screen. Luckily no one monitors what I do or where I go during the day, but to be fair almost everyone in the company is actively job hunting. For onsites I'd probably work from home for a bit and take the rest of the day off.