hmm, whats the problem here ??

stuartc1

I am looking to create a new date with either adding or subtracting a dynamic number of days from it.

$days_to = 2; // this value will be passed in, it may contain a negative int


if ($days_to >0) {
	$offset = $days_to;
	$op = "+";
} else {
	$offset = $days_to;
	$op = "-";
}

$new_date = date("d-m-Y", mktime (0,0,0,date("m"),date("d")$op.$offset, date("Y")));

the above line will through a parse error. any ideas ??

cheers

michaelruck

$days_to = 2; // this value will be passed in, it may contain a negative int

if ($days_to >0) {
$offset = $days_to;
} else {
$offset = -$days_to;
}

$new_date = date("d-m-Y", mktime (0,0,0,date("m"), date("d")+$offset, date("Y")));

bernouli

which error then?

stuartc1

$new_date = date("d-m-Y", mktime (0,0,0,date("m"), date("d")+$offset, date("Y")));

The above will only work with positive values, it needs to support negative ones too.

The error I get is:
Parse error: parse error in C:\Inetpub\wwwroot\intranet\php\hr\tsheet\copy.php on line 30

where line 30 = the $new_date = date(.....); as per my post.

if I code it and replace $op.$offset with say +2 then it works !

michaelruck

it's not allowed to concatenate strings in a function (the Dot operator).

Try this:

<?php
$the_date = date("d-m-Y", mktime (0,0,0,date("m"), date("d"), date("Y")));
$new_date = date("d-m-Y", mktime (0,0,0,date("m"), date("d")+$days_to, date("Y")));

echo "The Date: $the_date<br>";
echo "<form type='POST' method='POST' action=''>Days to: <input type='text' name='days_to' value='$days_to'>\n";
echo "<input type='submit' name='Submit' value='check'></form>";
echo "New Date: $new_date";
?>

stuartc1

cheers, but the problem here is that we are unaware whither the value will be positive (+) or negative (-) so we need to dynamically create this value in the mkdate function.

If the dynamic value is positive it will apear as 2 (without the + operator).
If the dynamic value is negative it will apear as -2 (with the - operator).

how is it possible to build this into the function with the correct operator ?

stuartc1

OK, I know what to do now:

$offset = $s_day_from_now;
if ($offset >0) {

$s_year = date("Y", mktime (0,0,0,date("m"),date("d")+$offset, date("Y")));
} else {
$s_year = date("Y", mktime (0,0,0,date("m"),date("d")-$offset, date("Y")));
}

easy🙂

michaelruck

now I know what you need.

with the abs function you can get rid of the if-statement

abs(-1) returns 1
abs(1) returns 1

your codeline now:

$s_year = date("Y", mktime (0,0,0,date("m"),date("d")+abs($days_to), date("Y")));