Converting Seconds to hh:mm:ss format without using Interval() function

[vlad_komarov]

Hello,

I have a data set where some time values are presented in seconds. Data on the chart should be displayed in hh:mm:ss format.

I've used the Interval() function in the script:

     Interval(time_field/86400, 'hh:mm:ss') as TIME_VALUE

and everything was looking good.

But,

I need to avoid any data transformation in my script and simply rely on data from the database.

I was hoping that using the same approach on the data side (code from the View Script):

     CAST (TIME_SEC / 84600 AS NUMBER (20, 18)) AS TIME_FULL

will work the same way, but I've noticed some rounding (?) issues.

With small values in seconds, everything looks good:

With values growing, the error increases:

And the difference reaches significant values when time in seconds represent large interval (more than 2 minutes difference in ~1,5 hours range....):

I could not find any reasonable explanation for that.

I would appreciate any suggestions.

Regards,

Vladimir

[tresesco]

It is possibly answered here: http://community.qlik.com/blogs/qlikviewdesignblog/2013/12/17/rounding-errors

[danieloberbilli]

http://qlikviewcookbook.com/2011/10/correct-time-arithmetic/

I agree with tresesco - this is the right source. Especially have a look at Robs comment: avoid using division to convert time.

See also the link above

[jonathandienst]

Hi

You want to avoid transforming the data in QV - that's fine. Interval() does not transform the data, it simply formats to hh:mm:ss (or other format that you specify) - the underlying data value is unchanged.

You can prove this to yourself by entering something like this in a text box:

     =Num(Interval(3233))

Num gets the underlying value...

HTH

Jonathan

[vlad_komarov]

Jonathan,

Regardless the transformation definition:

Why TIME_1 and TIME_2 are significantly different?

	Interval(TIME_SECONDS/86400, 'hh:mm:ss') as TIME_1,
	Interval(TIME_DIV_BY_86400, 'hh:mm:ss') as TIME_2,

Somehow QV know how to round the value correctly??

[vlad_komarov]

It's good article and nice discussion , but it's still not clear for me why QV's Interval() function works better in this case...

Interval(TIME_SECONDS/86400, 'hh:mm:ss') as TIME_1,   // result is correct

Interval(TIME_DIV_BY_86400, 'hh:mm:ss') as TIME_2,       // result is wrong

Somehow QV know how to round the value correctly??

[vlad_komarov]

Excel works perfectly too...

SECONDS	SECONDS/86400	EXCEL FORMATTED
5865	0.067881944444444400	1:37:45