Zend PHP 7 Certification – Data Formats and Types – Date and Time

15th October 2017

This post covers the Date and Time section of the Data Formats and Types chapter when studying for the Zend PHP 7 Certification.

Date and time functions retrieve date and time data from the PHP server.

The date() function formats a local time/date. There are several options of the format you can output. Some of them can be seen below.

  • l – A full textual representation of the day of the week i.e. Monday
  • D – Textual representation of the day of the week in three characters i.e. Mon
  • d – Day of the month, 2 digits with leading zeros i.e. 01, 31
  • j – Day of the month (digits) without leading zeros i.e. 1, 31
  • S – Suffix for each day of the month i.e. st, nd, th
  • W – Week. i.e. 42 for the 42nd week of the year
  • F – Full textual representation of the month i.e. January
  • M – Month number. 2 digits with leading zeros i.e. 01, 12
  • m – Month number in three characters i.e. Jan, Dec
  • n – Month number. 2 digits without leading zeros i.e. 1, 12
  • Y – 4 digit year number i.e. 1999, 2003
  • y – 2 digit year number i.e. 99, 03
  • g – 12 hour format of the hour without leading zeros i.e. 1, 12
  • G – 24 hour format of the hour without leading zeros i.e. 1, 18
  • h – 12 hour format of the hour with leading zeros i.e 01, 12
  • H – 24 hour format of the hour with leading zeros i.e. 01, 18
  • i – Minutes with leading zeros i.e. 04, 59
  • s – Seconds with leading zeros i.e. 02, 56
  • A – AM or PM
  • a – am or pm
<?php
// set the default timezone to use. Available since PHP 5.1
date_default_timezone_set('UTC');

// Prints something like: Monday
echo date("l");

// Prints something like: Monday 8th of August 2005 03:12:46 PM
echo date('l jS \of F Y h:i:s A');

// Prints: July 1, 2000 is on a Saturday
echo "July 1, 2000 is on a " . date("l", mktime(0, 0, 0, 7, 1, 2000));

getdate() gets date/time information. The optional timestamp parameter is an integer Unix timestamp that defaults to the current local time if a timestamp is not given.

For example, to get today’s date:

<?php
$today = getdate();
print_r($today);

The time() function returns the current time measured in the number of seconds.

<?php
$nextWeek = time() + (7 * 24 * 60 * 60);
                   // 7 days; 24 hours; 60 mins; 60 secs
echo 'Now:       '. date('Y-m-d') ."\n";
echo 'Next Week: '. date('Y-m-d', $nextWeek) ."\n";

// Outputs:
Now: 2016-05-08 
Next Week: 2016-05-15

The strtotime() function expects to be given a string containing an English date format and will try to parse that format into a Unix timestamp (the number of seconds since January 1 1970 00:00:00 UTC

<?php
echo strtotime("10 September 2000"), "\n";

// Outputs:
968536800

You can also pass a string such as the following examples shown below.

echo strtotime("now"), "\n";
echo strtotime("+1 day"), "\n";
echo strtotime("+1 week"), "\n";
echo strtotime("+1 week 2 days 4 hours 2 seconds"), "\n";
echo strtotime("next Thursday"), "\n";
echo strtotime("last Monday"), "\n";

The DateTime class can be used to represent the date and time.

It contains a few methods such setDate(), which sets the date of a DateTime object.

<?php
$date = new DateTime();
$date->setDate(2001, 2, 3);
echo $date->format('Y-m-d'); // Outputs: 2001-02-03

setTime() sets the time of a DateTime object.

<?php
$date = new DateTime('2001-01-01');

$date->setTime(14, 55);
echo $date->format('Y-m-d H:i:s') . "\n"; // Outputs: 2001-01-01 14:55:00

The add() function adds an amount of days, months, years, hours, minutes and seconds to a DateTime object.

<?php
$date = new DateTime('2000-01-01');
$date->add(new DateInterval('P10D')); // 10D means add 10 days
echo $date->format('Y-m-d') . "\n"; // Outputs: 2000-01-11

View the other sections:

Note: This article is based on PHP version 7.0.