The authors are grateful to Dr. Schonberger for his thoughtful comments with respect to our recent manuscript entitled “Observations on Surgical Demand Time Series: Detection and Resolution of Holiday Variance.”1 

Dr. Schonberger's speculations regarding the Jewish lunar calendar are astute, and we believe they may have merit. We are investigating these nontrivial cycles of surgical demand further and hope to determine a definitive answer in the near future.

*Hospital University of Pennsylvania, Philadelphia, Pennsylvania.

Moore IC, Strum DP, Vargas LG, Thomson DJ: Observations on surgical time demand series: Detection and resolution of holiday variance. Anesthesiology 2008; 109:408–16