3 Replies Latest reply on Mar 1, 2018 9:32 AM by Shinichiro Murakami

    Educational Brain Teaser(Answer Part I) : Graph of "Time" replicates Excel (Easy?)

    Shinichiro Murakami

      Question : Educational Brain Teaser : Graph of "Time" replicates Excel (Easy?)


      This post does not include final answer yet, but describing about "1 sec" Delta.


      I had initially thought that it is easy fix, but actually, when I look into replied workbook, even using exact same formula, answer  is different.


      Someone's file.



      Original File.



      From here, i will show my endeavor to investigate this delta.




      Check Excel logic with manually type specific date/time, and convert that to floating numbers..



      Same thing on Tableau.


      It looks like the "start date(1900/1/1, 1899/12/31 or something)" is different, but smaller than decimal point seems same value.




      Check the point  "Second" changes on excel with changing extremely small value.,


      It looks like that rounding with "Second" unit, (24 [hour] X 60 [minute] X 60 [second] matched the point of "second" changes.


      So, I applied same logic on Tableau formula.







      Lets' check the value.


      Seems OK with new start and end time.


      i think there are several chances to have different numbers as data srouce such as

      - version of OS

      - version of Excel

      - Connect to the file or data table copy/paste

      - version of Tableau


      In any case, the start tiem and end time shows exact same value as format of [yyyy/mm/dd h:mm:ss]

      But if mil-sec level value is different, you might get different delta.

      That's easily captured display number and real number difference if the format os standard numbers.

      But in case of "date/time", it is pretty troublesome as its feature...


      All pf above explanation is 100% unexpected fluctuations and  still data preparation stage, and I will explain the intent of this teaser next time.

      Attaching validation excel only.


      Enjoy Tableau !




      Shinichiro Murakami