[SOLVED] comparing date values

[Vidya_tr]

I have two dates in varaibles $fromdate and $todate

my $todate should be always greater than $fromdate

an if() condition checks for the valid dates...if they are the same an error message is produced.

suppose i have the values..

$fromdate="2009-05-03 09:00:00" and $todate="2009-05-03 09:00:00" (the values are taken from database and are of type DateTime.)

<?php
if($todate==$fromdate)
 {
 echo "You entered a Wrong date/time.Please enter the Date/Time correctly";
 exit;}
?>

 

But here the error message is not produced....

Is there any problem in comparing the DateTime values????

[PFMaBiSmAd]

That code works correctly for me with those values.

 

Have you checked if $fromdate and $todate actually contain what you think they do? Is that piece of code even being executed? Is it inside of a conditional block of code that is being bypassed because of a FALSE value?

[Vidya_tr]

my values are correct ..

Even if I put the code like this..

<?php
if($todate<=$fromdate)

{
 echo "You entered a Wrong date/time.Please enter the Date/Time correctly";
 exit;}
?>

 

it checks the less than value and produces the message but not the equal to value...

Can I check this in some other way???

[Ken2k7]

Can you post the output of:

 

var_dump($todate);

 

and

 

var_dump($fromdate);

 

Thanks!

[Vidya_tr]

<?php
I get the values of date by posting from another form
$fromdate=date('Y-m-d',strtotime($_POST['year1']."-".$_POST['month1']."-".$_POST['day1']));
$fromtime=strftime('%H:%M:%S',strtotime($_POST['hrs1'].":".$_POST['min1']));
$from=$fromdate." ".$fromtime;

$todate=date('Y-m-d',strtotime($_POST['year2']."-".$_POST['month2']."-".$_POST['day2']));
$totime=strftime('%H:%M:%S ',strtotime($_POST['hrs2'].":".$_POST['min2']));
$to=$todate." ".$totime;

/*Suppose I get the posted value as 
$fromdate=2009-05-03
$fromtime= 09:00:00
Then I have $from= 2009-05-03 09:00:00
(same values in $toddate ,$totime)*/

//function call to check valid date and time
checkDateTime($from,$to);
function checkDateTime($fromdate,$todate)
{
if($todate<$fromdate)
{ echo "You entered a Wrong date/time.Please enter the Date/Time correctly";
 exit;}
 if($todate==$fromdate)
 { echo "You entered a Wrong date/time.Please enter the Date/Time correctly";
 exit;}
}	

?>

 

(I am not retrieving the dates from database.sorry there was a mistake in what I told u before)

 

[ignace]

<?php
   if($todate<$fromdate)
   { echo "You entered a Wrong date/time.Please enter the Date/Time correctly";
    exit;}
    if($todate==$fromdate)
    { echo "You entered a Wrong date/time.Please enter the Date/Time correctly";
    exit;}
?>

 

is the same as

 

<?php
   if($todate<$fromdate || $todate==$fromdate)
    { echo "You entered a Wrong date/time.Please enter the Date/Time correctly";
    exit;}
?>

 

Maybe you can use something like:

 

list($date, $time) = explode(' ', $_POST['fromdate']);

list($year, $month, $day) = explode('-', $date);

list($hour, $minute, $second) = explode(':', $time);

 

$fromdate = mktime($hour, $minute, $second, $month, $day, $year);

 

However these kind of dates aren't really practical especially not for the end-user try creating some regular expression if you can not create one then you may be able to find one on: http://regexlib.com/

[PFMaBiSmAd]

The reason your code does not work is because the format string in the following contains an extra space after the %S

 

$totime=strftime('%H:%M:%S ',strtotime($_POST['hrs2'].":".$_POST['min2']));

 

Had you done what Ken2k7 suggested in his post, you would have discovered this.

[ignace]

besides what probably everyone forgot was that php can not compare dates only mysql can when you do this:

 

  if($todate<$fromdate) then you are comparing strings which means you are comparing there ascii value, example:

 

if ("A" > "a") 65 > 97 == false

 

so what you need to do is change the date into an integer and compare these therefor you can use my method and then

 

if ($from_unixtime < $to_unixtime) you will get the resulsts you need

[PFMaBiSmAd]

The posted code works, after the extra space in the formatting is removed.

 

If strings have the same format and the fields that make up the string are arranged from MSD (most significant digit - year) to LSD (least significant digit - second), then you can perform comparisons on them. This is why DATE and DATETIME values in a database are defined the way they are MSD to LSD.

[ignace]

@PFMaBiSmAd That is very interesting i never though about it that way nevertheless i tested it and it didn't work, tried both:

 

<?php
if ("1-1-2009" > "31-12-2008") {
    echo "yep!";
} else {
    echo "nope!";
}
?>

 

<?php
if ("01-01-2009" > "31-12-2008") {
    echo "yep!";
} else {
    echo "nope!";
}
?>

 

Both say nope!

[PFMaBiSmAd]

Read what I posted. They must be in the same format (each field must be the same length) and the fields must be from MSD to LSD.

[Vidya_tr]

yes It worked after the space was removed..

thanks for the help...

[ignace]

The posted code works, after the extra space in the formatting is removed.

 

If strings have the same format and the fields that make up the string are arranged from MSD (most significant digit - year) to LSD (least significant digit - second), then you can perform comparisons on them. This is why DATE and DATETIME values in a database are defined the way they are MSD to LSD.

 

So you arrange a string from msd to lsd by converting it to an integer, correct?

[PFMaBiSmAd]

No.

 

YYYY-MM-DD HH:MM:SS is MSD to LSD for a datetime, like I already stated -

 

MSD (most significant digit - year) to LSD (least significant digit - second)