We simply ignore DST. For example let&#x27;s take a recurring event that happens every Wednesday at 6pm for 10 weeks. In the middle of those 10 weeks, this timezone enters DST.<p>By saving the series&#x27; time as 6pm EST in the database, we can save all the individual occurences without having to do any check for DST changes in the middle of the series.<p>The users are simply interested in knowing when their yoga class is, the class is at 6pm, that&#x27;s it. Before or after DST change, it&#x27;s still 6pm.<p>Edit : Even if we had locations that were running 24&#x2F;7, I don&#x27;t think there would be any issue. An event that starts at 10pm and ends at 4am after a DST change? Any good datetime library will tell you that the event runs for either 7 or 5 hours, when calculating difference between those 2 datetimes when knowing the proper timezone. We&#x27;re using C# and the standard .Net datetime library is one of the best I&#x27;ve ever worked with.