We use a mixture of strategies
We have about 65 people handling over 160,000 calls a year. Big desk, big volume and only growing. But yes, during the holidays, things slack off a bit. So we use a mixture of strategies.
First, people can take off -- but, they can only take off one of the Big Three: day after Thanksgiving, Christmas Eve or New Year's Eve. We are officially closed, with on-call for emergencies, on the three "days" themselves. We were asked to work Thanksgiving (we service Canada and Puerto Rico as well as the U.S.) until we showed by metrics that it simply wasn't worth staffing the desk for the 5 or 6 calls that did come in.
Second: first come, first served with two caveats -- if your performance is below expectations, you go to the back of the line. And if two people ask for the same slot at the same time, seniority wins.
Third: shift work. The people that remain on the desk on those really slow days (this year, we've actually had several due to real doldrums between Xmas and New Year's) may be allowed to go home early or work half-shifts if the call volume permits. This may be scheduled (the "eves" and "day after" usually are), or it may just be the manager or team lead looking at the call volume and shaving an hour or two here and there off peoples' shifts.
Note to Nick: Better to keep family status assumptions out of the mix. It's dreadfully close to making a prejudicial judgment based on marital status. The singles may be traveling to spend Christmas or Thanksgiving with distant family. The families may be hosting the dinner or the New Year's eve party. Shoot, the SINGLES may be hosting the dinner for the family to join them.
