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wannab0133
Known Participant
June 5, 2015
Answered

convert datetime to decimal

  • June 5, 2015
  • 1 reply
  • 1530 views

Does anyone know of a way to convert a datetime (like 2015-06-10 07:30:00) to a decimal, similar to:

42165.450 where 42165 is days and 450 is minutes?  If I try the following:

------------------------------------------------------------------

<cfset dtNow = "2015-06-10" />

<cfset dtOne = CreateDateTime(

    Year( dtNow ),

    Month( dtNow ),

    Day( dtNow ),

    07, <!--- 6 PM. --->

    30, <!--- 30 Minutes. --->

    00 <!--- 0 Seconds. --->

    ) />

<!--- Dump out result. --->

<cfdump var="#NumberFormat(dtone,'99999.99999')#" /><br>

------------------------------------------------------------------

I end up with 42165.31250

Thanks

    This topic has been closed for replies.
    Correct answer BKBK

    Padding with zero is not the answer. What you are actually writing as .720 and .1218 are, in fact, not decimals.

    As you yourself have suggested, the values 720 and 1218 stand for number of minutes. Thus, the time, in minutes, corresponding to the dates (2015-06-16 at 12:00) and (2015-06-16 at 20:18) are, respectively, 12x60=720 and 20x60+18=1218. You can solve the problem in 2 ways:

    1)

    Interpret the values 42170 / 720 and 42170 / 1218, respectively, as 42170+720/1439=42170.500 and 42170+1218/1439=42170.846

    2)

    Take a step back to my last post. You can determine the zero-date of your system as follows.

    You know that the date (2015-06-16 at 12:00) is equivalent to (42170 days + 720 minutes) after the zero-date. Converting everything into minutes gives (42170 x 24 x 60 + 720) minutes =  60725520 minutes. You then have


    <!--- Test date is 2015-06-16 at 12:00 --->

    <cfset myTestDate = createdatetime(2015,06,16,12,0,0)>

    <!--- Zero date is 60725520 minutes prior to test date --->

    Zero date: <cfoutput>#dateAdd("n",-60725520,myTestDate)#</cfoutput>

    This tells you that your zero date is 1899-12-30 23:00, which is equivalent to createDatetime(1899,12,30,23,0,0). You can then use this zero-date as the basis for all further date calculations.

    Suppose you wish to find any date corresponding to the format number_of_days / number_of_minutes, for example, 42170 / 1218. All you now have to do is convert everything into minutes and add to the zero date. Thus,

    <cfset zeroDate = createdatetime(1899,12,30,23,0,0)>

    <cfset newDate = dateAdd("n",42170*24*60+1218,zeroDate)>

    <cfoutput>#newDate#</cfoutput>

    1 reply

    BKBK
    BKBK
    Community Expert
    June 5, 2015

    There is actually no such thing as a conversion of a date to a number of days. Methods like #NumberFormat(dtone,'99999.99999')# or #dtone+0# are unofficial.

    The proper way to do it is to convert a time period into days. So you first have to define your 'zero' date.

    In Coldfusion, the zero date is 12 A.M., December 30, 1899. But it is usually, rather confusingly, given the value createdatetime(1899,12,29,12,0,0). Hence.

    <cfset cfZeroDate = createdatetime(1899,12,29,12,0,0)>

    <cfset myTestDate = createdatetime(2015,06,10,07,30,0)>

    <!--- Number of days = (number of hours in time period)/24 --->

    <cfoutput>#datediff("h",cfZeroDate,myTestDate)/24#</cfoutput><br>

      W
      wannab0133Author
      Known Participant
      June 13, 2015

      It turns out that the data I am using is storing days as integers(days from 12-30-1899), and times as integer(minutes from midnight i.e 0-1439).  So I am concatenating like this: days.minutes  But, I am having an issue comparing the foillowing:

      42170.720(2015-06-16 at 12:00) vs 42170.1218(2015-06-16 at 20:18)

      It is telling me the first date at noon is GT the other date.  So, I need to pad the times with zeros, so it becomes 42170.0720 instead of 42170.720.  My qoq is here:


      <cfquery name="dutyEndQuery" dbtype="query">

              SELECT * FROM refData

              WHERE EMPLOYEEID = '#passedEmployeeID#'

              AND  CAST( CAST(ACTIVITYDATE as VARCHAR) + '.' + CAST(ACTIVITYTIME as VARCHAR) AS DOUBLE ) >= #passedDutyDateTime#

          </cfquery>

      Is there anyway in a qoq to pad the time portion with zeros and make the total size 4 in order to change 720 to 0720?

      BKBK
      BKBKCorrect answer
      Community Expert
      June 14, 2015

      Padding with zero is not the answer. What you are actually writing as .720 and .1218 are, in fact, not decimals.

      As you yourself have suggested, the values 720 and 1218 stand for number of minutes. Thus, the time, in minutes, corresponding to the dates (2015-06-16 at 12:00) and (2015-06-16 at 20:18) are, respectively, 12x60=720 and 20x60+18=1218. You can solve the problem in 2 ways:

      1)

      Interpret the values 42170 / 720 and 42170 / 1218, respectively, as 42170+720/1439=42170.500 and 42170+1218/1439=42170.846

      2)

      Take a step back to my last post. You can determine the zero-date of your system as follows.

      You know that the date (2015-06-16 at 12:00) is equivalent to (42170 days + 720 minutes) after the zero-date. Converting everything into minutes gives (42170 x 24 x 60 + 720) minutes =  60725520 minutes. You then have


      <!--- Test date is 2015-06-16 at 12:00 --->

      <cfset myTestDate = createdatetime(2015,06,16,12,0,0)>

      <!--- Zero date is 60725520 minutes prior to test date --->

      Zero date: <cfoutput>#dateAdd("n",-60725520,myTestDate)#</cfoutput>

      This tells you that your zero date is 1899-12-30 23:00, which is equivalent to createDatetime(1899,12,30,23,0,0). You can then use this zero-date as the basis for all further date calculations.

      Suppose you wish to find any date corresponding to the format number_of_days / number_of_minutes, for example, 42170 / 1218. All you now have to do is convert everything into minutes and add to the zero date. Thus,

      <cfset zeroDate = createdatetime(1899,12,30,23,0,0)>

      <cfset newDate = dateAdd("n",42170*24*60+1218,zeroDate)>

      <cfoutput>#newDate#</cfoutput>

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