Thanks for the explanation and the work around is good 
So =(-6*3600+MID(A2,17,2)*3600+MID(A2,20,2)*60+MID(A2,23,2))/(24 * 3600) etc formula will do the trick. I dont mind the UTC and or converting if needed. My thought was that since the data from plots etc falls so nicely out into students spread sheets that having a format that XL can digest = ‘Format > Cells > Time’ or ‘Format > Cells > Date’ might be nice ?
I am happy enough as is but just a thought for a future refinement that the dump from plots widget might do this and leave the JavaScript date string for the slightly techier data querry buttons.
Happy to leave this as a suggestion or thought for now
Thanks for prompt reply.
~ Andrew