Comment by epmatsw

At least a few years ago, when I was at Epic (not on a medical-user-facing team), the issue that caused this wasn't the data storage of the timestamps or whatever. It's figuring out how to display events during that repeated hour in charts that assume 24 hour days in patient-safe way.

Say you see on the chart that a patient received medication at 1:30. It's now 2:30, and the patient is supposed to receive medication every 2 hours. Do you give them another dose? Did they get their does at the first 1:30 or the 2nd 1:30? Expand that by the literal thousands of super (almost frustratingly) customizable workflows, custom charts, etc., and the problem gets pretty big.

Considering most (maybe all?) Epic upgrades require brief downtimes, a lot of hospitals chose to take their downtime to install updates during the DST changeover time and rely on their doctors/nurses/etc. to be extra careful on paper during the doubled hour. Is it a great system? Not really. But it kind of works I guess.