Use only one calendar.
There is only one of you...one person with one life that needs managing with both work and play activities included. Using two calendars puts you at risk for missing an important event or not having the right device with you when you need it. Plus, managing more than one calendar means taking extra steps to manage multiple tools. If your employer won't let you share calendars, see if you can use a smart phone with a split screen that allows for two calendars to be appear on the same device. At least it's a step in the right direction.