PHP Day count function writing - php

Question

I need to Write a function named countDays which takes a single parameter named dateinstring which is string in the form ”MM.DD.YYY” represent a real date value. The function should print to the console the number of days from the beginning of the year specified in dateInString until the date represented in dateInString. If the value of dateInString is invalid, the function should print ”Bad format” to the console.
I have written the code as below :
function countDays($dateInString){
date_default_timezone_set('America/Los_Angeles');
$date = explode('.', $dateInString);
if(count($date) == 3 && checkdate($date[0], $date[1], $date[2])){
$formatted_date = $date[2].'-'.$date[0].'-'.$date[1].'00:00:00';
$diff = strtotime($formatted_date).'-'.strtotime($date[2].'-01-01 00:00:00');
echo round($diff/86400)+1;
}
else {
echo 'Bad format';
}
};
countDays('1.15.2014');
But the above code seems that not giving the correct output. It is about 33% correct. But where is the problem with this code ? Please help me!!!

Answer 1

$diff = strtotime($formatted_date).'-'.strtotime($date[2].'-01-01 00:00:00');
Change to
$diff = strtotime($formatted_date) - strtotime($date[2].'-01-01 00:00:00');
You made the minus symbol a string instead of an operator.

Answer 2

You could try it this way
function countDays($dateInString) {
date_default_timezone_set('America/Los_Angeles');
$date = explode('.', $dateInString);
if (checkdate($date[0], $date[1], $date[2])) {
$year_start = mktime(0, 0, 0, 1, 1, $date[2]);
$your_date = mktime(0,0,0,$date[0], $date[1], $date[2]);
$diff = $your_date - $year_start;
echo floor($diff /(60*60*24));
} else {
echo "Bad date supplied";
}
}

Answer 3

A better approach would be to use the DateTime class. I haven't included the validation in this, but i suggest you use regex for that.
function countDays($dateInString){
$parts = explode('.', $dateInString);
$date = new DateTime($parts[2] . '-' . $parts[0] . '-' . $parts[1]);
$compare = new DateTime( $date->format('Y') . '-01-01' );
$interval = $date->diff($compare);
return $interval->format('%a');
}
echo countDays('09.15.2014');

Answer 4

Check this out.
function countDays($dateInString){
date_default_timezone_set('America/Los_Angeles');
$date = explode('.', $dateInString);
if(count($date) == 3 && checkdate($date[0], $date[1], $date[2])){
$formatted_date = strtotime($date[2].'/'.$date[0].'/'.$date[1]);
$endTimeStamp = strtotime("2014/01/01");
$timeDiff = abs($endTimeStamp - $formatted_date);
echo round(intval($timeDiff/86400));
}
else {
echo 'Bad format';
}
};
countDays('01.01.2014');