Socal - John Lynch's FAA FAQ (I have a copy) would disagree with you, as would all DPEs to whom I have addressed the question, in years past
This is within the DPE's discretion.
Backpacker - interesting quote from Lasors. A statement like "a single day" has to have flexibility in it otherwise it would not make sense in any country where night flight without having to go formally IFR is permitted.
FWIW, I have always understood the "solo" meaning as nobody else in the aircraft, and this is what I was told under the FAA system. And under the UK system you are definitely not allowed to carry anybody either. For some people who have travelled extensively already, this will mean having to burn a few hundred litres of avgas specially to get this logbook entry.
Whopity - interesting that you interpret a "day" as a 24hr period. I can't disagree though... also the FAA CPL X/C requires three landings, not two.