Merge pull request #126 from tvlooy/datetime

some words about DateTime

_posts/05-03-01-DateTime.md

@@ -0,0 +1,42 @@
+---
+isChild: true
+---
+
+## Working with date and time
+
+Working with dates and time is very easy. PHP has a class named DateTime for this. Taking a sting and converting it to a DateTime is possible with the createFromFormat factory method. This method also has a non OO counterpart, named date_create_from_format().
+
+{% highlight php %}
+<?php
+$rawDate = '22/11/1968';
+$date = \DateTime::createFromFormat('d/m/Y', $rawDate);
+
+{% endhighlight %}
+
+Calculating with DateTime is possible with the DateInterval class. DateTime has functions like add() and sub() that take a DateInterval as an argument. For example, if one would want to add a month to the date we created above:
+
+{% highlight php %}
+$date->add(new \DateInterval('P1M')); // add a Period of one Month
+{% endhighlight %}
+
+The DateTime class has a function to format a date.
+
+{% highlight php %}
+echo $date->format('d/m/Y h:i:s');
+{% endhighlight %}
+
+One last example that demonstrates converting a Unix timestamp to DateTime and back to Unix timestamp:
+
+{% highlight php %}
+$unixtime = '1239363000';
+$date = DateTime::createFromFormat('U', $unixtime); // date is now 2009-04-10 11:30:00
+echo $date->format('U'); // outputs 1239363000
+{% endhighlight %}
+
+* [Read about DateTime][datetime]
+* [Read about DateInterval][dateinterval]
+* [Read about formatting date][dateformat]
+
+[datetime]: http://php.net/manual/en/language.exceptions.php 
+[dateinterval]: http://www.php.net/manual/en/class.dateinterval.php
+[dateformat]: http://www.php.net/manual/en/function.date.php