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 <

>Yes, I can confirm that but it's a bug, IMO. Michel?
>

>
>>It appears to me that the following behave equally in the filter
>>

>>> and >=
>>< and <=
>>

>>iow you get the same result with or without the equal sign
>>