Essential?

During the past couple of snow and ice events in Lexington, some of the large institutions in town have said that the non-essential employees did not have to come to work at their regular times.  When I heard this announcement, I wondered what makes one employee essential and another non-essential.  I made the assumption that essential employees are those who kept the institution functioning, ex., answering the telephones, paying bills, cleaning the sidewalks, etc.  Their announcement also made me ponder the question of whether or not I was essential.  I'm a Counselor and Spiritual Companion, so how essential is that?  I guess my question was answered by my clients and directees.  Some showed up for their appointments and other called in to re-schedule.  I did, however, go to the Center early on those days to clean our sidewalk and steps so, perhaps, I'm more essential than I sometimes think.