>>>Perhaps the time portion added to the search date is 00:00:00
>>>That would explain it - unless you post exactly at midnight
>>>
>>>

>>>> and >=  is always >=
>>>< and <=   is always <
>>>

>>>
>>I would say, it's because of the time portion, so > and >= will behave the same.
>
>
>Isn't that what I wrote ?

Yes, I just confirm it.