SSAS 2012 Calculated Member in "hh:mm:ss" does not work

Question

I've seen a lot of posts that suggest this should work for displaying a calculated member in hours:minutes:seconds, but it doesn't in my 2012 developer environment.  I don't care that this specific code isn't accurate if the duration in seconds is over
a day long at this point.  It seems no matter how I try to format this, the result is the same.
[Measures].[Phase Duration Seconds] is an integer, and it doesn't seem to matter what goes in the FORMAT_STRING parameter, it comes out in SSMS, and SSDT as a decimal number.
CREATE MEMBER CURRENTCUBE.[Measures].[Phase Duration]
 AS [Measures].[Phase Duration Seconds] / 86400, 
FORMAT_STRING = "hh:mm:ss", 
VISIBLE = 1  ; 
If I write this as an MDX script, it works in SSMS, with or without the extra code to account for durations beyond a day:
with member [Measures].[Phase Duration] as [Measures].[Phase Duration Seconds] / 86400,
     format_string = IIF([Measures].[Phase Duration Seconds] / 86400 < 1,'"0 days" hh:mm:ss','"' + cstr(int([Measures].[Phase Duration Seconds] / 86400)) + ' days" hh:mm:ss')
select
        [Measures].[Phase Duration Seconds],
        [Measures].[Phase Duration]
   } on 0,
      [Phase].[Phase].Members
   } on 1
from [SSASDB]
Cheers and many thanks for any guidance,
Simon

Answer 1

After much trial and error, am I just barking up the wrong tree?  
I just learned about the deprecation of the abilities of the browser in Analysis Services 2012, and started using Excel instead...  The original code above to create a calculated member does work in Excel.
Cheers and thanks,
Simon
Cheers and thanks, Simon