5 Replies Latest reply on Sep 24, 2018 4:14 AM by Ivan Varga

    Daylight saving in Tableau

    Ivan Varga



      I am struggling few days with a way Tableau handles daylight saving time.


      Lets take 25.3. for example when daylight saving happens, timezone Bucharest (EET zone, moves from UTC+2 to UTC+3). Daylight saving happens at 3am and 3am moves to 4am. Result of this is that we have 23 hours in day.


      I attached workbook that demonstrates the problem, made in Tableau Desktop 10.5.5. Data source has 2 columns.

      • First column has timestamps for every 15 min block from 24.3. to 26.3. Important to note is that there is no 4 rows for 3am on 25.3 because of mentioned daylight saving.
      • Second column has values that go from value 1 from "oldest" timestamp and adds 0.1 to every following one. On 25.3. at 2:45 value is 11.3 and in next time period, 4:00 - value is 11.4.


      After joining these 2 tables, you would expect that day will have 23 hours. And you would expect that hours in a day will go as usual but without 3am (1am, 2am, 4am, 5am...).

      Result in Tableau is that day has again 24 hours. As you will see in attached example Tableau shows 4am twice on x-axis and you will also notice that only the second 4am timestamp has value which renders as a large gap between 2:45 and the second 4:00 timestamp on graph.


      I couldn't find any documentation on this, does anyone know how Tableau usually handles daylight saving?