Setting Php and Mysql timestamp - php

Question

I need to set timestamp eg. 4 hours ahead and 2 hours ahead separately
In my database, I have their columns as timestamp.
I know I could do something similar to this but am not sure if it's correct.
// For 4 hours ahead of time
$dt2 = date("Y-m-d 04:i:s");
//For 2 days ahead
$dt2 = date("Y-m-02 H:i:s");

Answer 1

//For 4 hours ahead of time
$dt2 = date("Y-m-d H:i:s", strtotime('+4 hours'));
//For 2 days ahead of time
$dt2 = date("Y-m-d H:i:s", strtotime('+2 days'));

Answer 2

In my mind it's much better to work with DateTime field and the DateTime class.
You have the ability so modify that objects very easily. For example:
$aktDate = new \DateTime();
Now you have the actual date and time in an object. If you want you can put a string insight the DateTime function so set your date manually.
$aktDate = new \DateTime('Y-m-d 04:i:s');
Not you can modify your dates if you want with the modify function.
in your case:
$pastDate = clone $aktDate;
$pastDate->modify('+2 days');
$futureDate = clone $aktDate;
$futureDate->modify('+4 days');
if($pastDate < $aktDate && $aktDate < $futureDate) {
// do something
}
I like the DateTime function much more because it's readable and you can work directly with your DateTime fields from your MySQL database if you have such fields. You can write that example much shorter but so you have better readability.

Answer 3

$date = new DateTime('now');
$date->modify('+2 days');
echo $date->format('Y-m-d H:i:s');
$date = new DateTime('now');
$date->modify('+4 hours');
echo $date->format('Y-m-d H:i:s');

Answer 4

You need to use the strtotime() function (http://php.net/manual/en/function.strtotime.php).
For your examples:
//+2 hours<br>
strtotime("+2 hours");
// +2 days<br>
strtotime("+2 days")
Edit: for what you ask, about posted values, the syntax is like this:
strtotime("+2".$_POST['field_name']." days");
You can use hours/days/months/weeks/years and either + or -