Creating and handling dates with PHP date

Next, we will see how to use PHP’s date function and how to format it to be displayed:

Content:

• Introduction
• Formats
• What is a timestamp?
• Using the strtotime function

Introduction

In PHP we can both create and format a date using the date() function.

Its syntax is as follows:

date ( string $format [, int $timestamp = time() ] ) : string

As you can see in the date function, it has 2 parameters, 1 optional, and it returns a string.

$format defines the format of our date, for example, day-month-year.

$timestamp is a UNIX timestamp value that represents the date. If this parameter is not provided, it will take the default value which is the current time using the time() function.

The time() function returns the current Unix timestamp value, but please note that this date is not the date of your user, it’s the date of the server.

Formats

Having explained this, let’s see the formats for the first parameter:

La tabla anterior es tal cual una referencia a la tabla que hay en la página de PHP.

<?php

echo "<h1>Ejemplos con date</h1>";

echo "<p>con formato dia mes año</p>";
echo date("d-m-y");
echo "</br>";
echo date("d-m-Y");
echo "<p>Un ejemplo con timestamp:</p>";
echo date("d-m-Y",0);
echo "<h2>Manejando horarios</h2>";
echo "<p>hora de ahora</p>";
echo "<p>Horas de 0 a 23</p>";
echo date("H:i:s");
echo "<p>Horas de 0 a 12</p>";
echo date("h:i:s");
echo "<p>Algo más complejo</p>";
echo date("l d, F Y H:i:s");
 ?>

The separators in the date format are indicated by symbols such as ., , -, /, and even space. Let’s take a look at another example to illustrate this further:

echo date("l:. d:. F:. Y:.");

¿What is the Timestamp?

Before finishing the topic of the date() function, note that in the example where we pass a timestamp, it will give us the date of December 31, 1969.

This is the Unix time:

Unix time or POSIX time is a system for describing points in time. It is defined as the number of seconds that have elapsed since midnight UTC on January 1, 1970.
Wikipedia

In other words, the first date will be January 1, 1970, Greenwich location. More specifically, it would be Date (UTC)Jan 1, 1970, 00:00:00.

Let’s do 2 more examples with this date.

echo date("d-m-Y H:i:s",0);
echo date("d-m-Y H:i:s",1);

01-01-1970 00:00:00
01-01-1970 00:00:01

Why the example does not give the correct day?, as that depends on the time zone, if we set it to the London time zone it should give us the correct date.

We can do this with the function date_default_timezone_set(‘UTC’); or date_default_timezone_set(‘Europe/London’);

date_default_timezone_set('UTC');

Utilizando strtotime()

Now, if I have a date as a string, how can I pass it to the date function? Obviously, I’m not going to calculate the timestamp to pass it.

The strtotime() function allows us to pass a date in string format and convert it to a timestamp (int). The format that must be passed to this function is in English, "m/d/y" or "y-m-d".

Let’s make some examples of strtotime():

echo date("jS F, Y", strtotime("11/12/10"))."\n";
echo date("jS F, Y", strtotime("11-12-10")); 

12th November, 2010
10th December, 2011

Other interesting things we can do with strtotime is to pass a string like "+2 month", for example.

We can even pass a date plus another string, for example, "10/10/10 +1 day" or "next Monday", both of which should work.

echo date("jS F, Y", strtotime("10/10/10 +1 day")); 

11th October, 2010

Finally, I want to make it clear that there are libraries that can greatly assist with date management, such as Carbon, which can be found on packagist.org.