Issue 105344

I'm working with a spreadsheet which uses the MM:SS.00 time format to do
calculations on running and swimming times. I enter that it took me 17 minutes
and 9 seconds (17:09.0) to run 2 miles, and the spreadsheet then calculates that
this was a pace of 08:34.50 per mile, and 02:08.63 per quarter mile. This all
works fine, as long as I enter the number as either 17:09.0 or 0:17:09 Entering
0:17:09.0 works fine too, as might be expected. 

But all three of these data entry formats involve the typing of extra zeros. The
format I'd prefer to be able to type is simply 17:09. But when I do this, Calc
makes some bad assumptions about which parts of the number to assign to minutes,
seconds, etc. It decides that "09" must be the number of minutes, and just
throws out the "17" since there isn't a place for hours in the MM:SS.00 format.

It seems like it should be easy to have the input function correctly deduce from
just the input "17:09" that "17" is minutes and "09" is seconds, since there are
no hours in the MM:SS.00 format.

I find this same behavior both when typing data and when cutting and pasting
data from a text file.