1 Reply Latest reply on Jan 3, 2016 11:00 AM by BKBK

    DateConvert() vs DateAdd() inconsistency question

    SemperVI Level 1

      I am working on some Date Helper functions where I need to convert UTC dates to unixtimestamps and vice versa. Interestingly I came across an inconsistency using the DateConvert function in cooperation with DateDiff in that the timestamps are different. DateConvert makes the timestamp using local time while DateAdd uses the appropriate UTC Date. I was wondering if this is a bug / anomaly or my misunderstanding how DateConvert works in ColdFusion.

       

      The following is syntax to reproduce scenario

      <cfset unixEpoch = CreateDate(1970,1,1) />

      <cfoutput>

          <pre>

          Local Date:        #Now()# [CORRECT]

          UTC Date:          #DateConvert("local2Utc", now())# [CORRECT]

          =======================================================

          UTC to Unix Timestamp Conversion

          =======================================================

          UTX (DateConvert): #DateDiff("s", unixEpoch, DateConvert("local2Utc", now()))# [WRONG]

          UTX (DateAdd):     #DateDiff("s", unixEpoch, DateAdd( "s", GetTimeZoneInfo().UTCTotalOffset, now() ) )# [CORRECT]

          </pre>

      </cfoutput>

      The following is what the above unit of code output last time I ran it

      Local Date: {ts '2015-12-30 10:44:25'} [CORRECT]

      UTC Date: {ts '2015-12-30 18:44:25'} [CORRECT]

      =======================================================

      UTC to Unix Timestamp Conversion

      =======================================================

      UTX (DateConvert): 1451472265 [WRONG]

      UTX (DateAdd): 1451501065 [CORRECT]

       

      *** Use http://www.unixtimestamp.com/index.php to confirm unix timestamp discrepancies

       

      Any thoughts would certainly be helpful -- Thank you

        • 1. Re: DateConvert() vs DateAdd() inconsistency question
          BKBK Adobe Community Professional & MVP

          I think you have stumbled on a bug. I have isolated it as follows:

           

          <cfset utcDate1 = dateConvert("local2Utc", now()) />

          <cfset utcDate2 = dateAdd( "s", getTimeZoneInfo().UTCTotalOffset, now()) />

              <cfoutput>

                  <pre>

                  UTC Date:                #utcDate1#

                 

                  Alternative UTC Date:      #utcDate2#

                 

                  Difference in UTC dates: #dateDiff("s", utcDate1, utcDate2)# seconds

                  </pre>

              </cfoutput>