6.1 PHP Date and Time

Get a Date

• The required format parameter of the date() function specifies how to format the date (or time).
• Here are some characters that are commonly used for dates:
  • d - Represents the day of the month (01 to 31)
  • m - Represents a month (01 to 12)
  • Y - Represents a year (in four digits)
  • l (lowercase 'L') - Represents the day of the week
• Other characters, like"/", ".", or "-" can also be inserted between the characters to add additional formatting.
• The example below formats today's date in three different ways:

Example 1: The PHP Date() Function - Get a Date

<?php
echo "Today is " . date("Y/m/d") . "<br>";
echo "Today is " . date("Y.m.d") . "<br>";
echo "Today is " . date("Y-m-d") . "<br>";
echo "Today is " . date("l");
?>

PHP Tip - Automatic Copyright Year

Use the date() function to automatically update the copyright year on your website:

Example 2: The PHP Date() Function - Automatic Copyright Year

&copy; 2010-<?php echo date("Y");?>

Get a Time

• Here are some characters that are commonly used for times:
  • H - 24-hour format of an hour (00 to 23)
  • h - 12-hour format of an hour with leading zeros (01 to 12)
  • i - Minutes with leading zeros (00 to 59)
  • s - Seconds with leading zeros (00 to 59)
  • a - Lowercase Ante meridiem and Post meridiem (am or pm)
• The example below outputs the current time in the specified format:

Example 3: The PHP Date() Function - Get a Time

<?php
echo "The time is " . date("h:i:sa");
?>

Note that the PHP date() function will return the current date/time of the server!

Get Your Time Zone

• If the time you got back from the code is not correct, it's probably because your server is in another country or set up for a different timezone.
• So, if you need the time to be correct according to a specific location, you can set the timezone you want to use.
• The example below sets the timezone to "America/New_York", then outputs the current time in the specified format:

Example 4: The PHP Date() Function - Get Your Time Zone

<?php
date_default_timezone_set("America/New_York");
echo "The time is " . date("h:i:sa");
?>

Create a Date With mktime()

• The optional timestamp parameter in the date() function specifies a timestamp. If omitted, the current date and time will be used (as in the examples above).
• The PHP mktime() function returns the Unix timestamp for a date. The Unix timestamp contains the number of seconds between the Unix Epoch (January 1 1970 00:00:00 GMT) and the time specified.

Syntax

mktime(hour, minute, second, month, day, year)

The example below creates a date and time with the date() function from a number of parameters in the mktime() function:

Example 5: The PHP Date() Function - Create a Date With mktime()

<?php
$d=mktime(11, 14, 54, 8, 12, 2014);
echo "Created date is " . date("Y-m-d h:i:s a", $d);
?<

Create a Date From a String With strtotime()

The PHP strtotime() function is used to convert a human readable date string into a Unix timestamp (the number of seconds since January 1 1970 00:00:00 GMT).

Syntax

strtotime(time, now)

The example below creates a date and time from the strtotime() function:

Example 6: The PHP Date() Function - Create a Date From a String With strtotime() part 1

<?php
$d=strtotime("10:30pm April 15 2014");
echo "Created date is " . date("Y-m-d h:i:sa", $d);
?>

PHP is quite clever about converting a string to a date, so you can put in various values:

Example 7: The PHP Date() Function - Create a Date From a String With strtotime()part 2

<?php
$d=strtotime("tomorrow");
echo date("Y-m-d h:i:sa", $d) . "<br>";

$d=strtotime("next Saturday");
echo date("Y-m-d h:i:sa", $d) . "<br>";

$d=strtotime("+3 Months");
echo date("Y-m-d h:i:sa", $d) . "<br>";
?>

However, strtotime() is not perfect, so remember to check the strings you put in there.

More Date Examples

The example below outputs the dates for the next six Saturdays:

Example 8: The PHP Date() Function - Create Dates From Strings With strtotime()

<?php
$startdate = strtotime("Saturday");
$enddate = strtotime("+6 weeks", $startdate);

while ($startdate < $enddate) {
  echo date("M d", $startdate) . "<br>";
  $startdate = strtotime("+1 week", $startdate);
}
?>

The example below outputs the number of days until 4th of July:

Example 9: The PHP Date() Function - Count The Number of Days To July 4 With strtotime()

<?php
$d1=strtotime("July 04");
$d2=ceil(($d1-time())/60/60/24);
echo "There are " . $d2 ." days until 4th of July.";
?>

Complete PHP Date Reference

• For a complete reference of all date functions, go to W3Schools.com complete PHP Date Reference.
• The reference contains a brief description, and examples of use, for each function!