error on unixstamp

In unixstamp function, the number 25569 is wrong. Making the calculation of the period between 1900 and 1970 in Excel the result will be that number, but the count starts from number one, then it is necessary to subtract this one. The correct value is 25568.

Sorry my english

give me your formula

function unixstamp( $excelDateTime ) {
$d = floor( $excelDateTime ); // seconds since 1900
$t = $excelDateTime - $d;
return ($d > 0) ? ( $d - 25568 ) * 86400 + $t * 86400 : $t * 86400;
}

Spasibo tebe Yuri

Hi friend, I did some testing and found another problem, but now, in my correction. I do not know if you've tested my function. The problem happens because of DST(Daylight Saving Time). I'm in Brazil and at the moment, we are in the summer time and this makes the function of converting dates do not work properly. So to fix this, I set the timezone to UTC.

function unixstamp( $excelDateTime ) {
date_default_timezone_set('UTC');
$d = floor( $excelDateTime ); // seconds since 1900
$t = $excelDateTime - $d;
return ($d > 0) ? ( $d - 25569 ) * 86400 + $t * 86400 : $t * 86400;
}

I hope to help me and excuse my bad english.