https://www.infopathdev.com:443/forums/41.aspxIf you're not sure where to ask your question, ask it here. If necessary, our moderators will make sure it gets classified in the correct board.enCommunityServer 2007 SP3 (Build: 31118.962)https://www.infopathdev.com:443/forums/thread/106728.aspxSun, 22 May 2016 22:45:28 GMT033a2e2d-04e2-4a9d-be01-a4634161eefd:106728Patrick Halstead0https://www.infopathdev.com:443/forums/thread/106728.aspxhttps://www.infopathdev.com:443/forums/commentrss.aspx?SectionID=41&PostID=106728<p>I recommend adding a rule to strip out the formatting from the text boxes using translate(StartTime, &quot;T-:&quot;, &quot;&quot;) and set the result to a secondary StartTime2 (or EndTime2). Then you should be able to calculate the difference more easily since there are no formatting characters.</p>https://www.infopathdev.com:443/forums/thread/106715.aspxFri, 20 May 2016 18:15:37 GMT033a2e2d-04e2-4a9d-be01-a4634161eefd:106715RisingsunND0https://www.infopathdev.com:443/forums/thread/106715.aspxhttps://www.infopathdev.com:443/forums/commentrss.aspx?SectionID=41&PostID=106715I am trying to add 2 time fields together to get a total time. Here are the 2 fields default values that I am adding together. The formula verifies but when I preview the form the field displays NaN. concat(substring(100 + number(concat(&quot;0&quot;, substring(EndTime, 1, 2))) - number(concat(&quot;0&quot;, substring(EndTime, 1, 2))), 2, 2), &quot;:&quot;, substring(100 + number(concat(&quot;0&quot;, substring(EndTime, 4, 2))) - number(concat(&quot;0&quot;, substring(StartTime, 4, 2))), 2, 2), &quot;:&quot;, substring(100 + number(concat(&quot;0&quot;, substring(EndTime, 7, 2))) - number(concat(&quot;0&quot;, substring(StartTime, 7, 2))), 2, 2)) + concat(substring(100 + number(concat(&quot;0&quot;, substring(FromEnd, 1, 2))) - number(concat(&quot;0&quot;, substring(FromStart, 1, 2))), 2, 2), &quot;:&quot;, substring(100 + number(concat(&quot;0&quot;, substring(FromEnd, 4, 2))) - number(concat(&quot;0&quot;, substring(FromStart, 4, 2))), 2, 2), &quot;:&quot;, substring(100 + number(concat(&quot;0&quot;, substring(FromEnd, 7, 2))) - number(concat(&quot;0&quot;, substring(FromStart, 7, 2))), 2, 2)) The 2 fields I am trying to add together are text box with Time data types, the field that I am trying to display the above formula in is text box with data type Text(string). Not sure how to fix it.