Advanced application Techniques for PHP date-time functions

A detailed explanation of the date and time function of PHP date ()Introduces the simple use of the PHP date-time function, which will introduce more functions to enrich our application.

checkdate ($month, $date, $year)

If the value that is applied constitutes a valid date, the function returns True. For example, for an error date of February 31, 2005, this function returns to False.

You can use this function to check the date and make the date effective before the date is calculated or saved in the database.

<?php
Returns false
echo checkdate (2,30,2005)? "Valid": "Invalid";
Returns True
echo checkdate (4,6,2010)? "Valid": "Invalid";
?>
getdate ($ts)

In the absence of an argument, the function returns the current date and time in a associative array. Each element in the array represents a specific component in the date/time value. You can submit an optional time label argument to a function to get the date/time value that corresponds to the time label.

This function is used to obtain a series of discrete, easily separated date/time values.

<?php
Get date as associative array
$arr = getdate ();
echo "Date is". $arr [' Mday ']. " " . $arr [' Weekday ']. " " . $arr [' Year '];
echo "Time is". $arr [' hours ']. ":" . $arr [' minutes '];
?>
mktime ($hour, $minute, $second, $month, $day, $year)

The function is the opposite of getdate (): It generates a UNIX time label from a series of date and time values (the number of seconds from GMT January 1, 1970 to the current elapsed). When the argument is not used, it generates the UNIX time label for the current time.

Use this function to get the UNIX time label for the instant time. This time tag is commonly used in many database and program languages.

<?php
Returns timestamp for 13:15:23 7-jun-2006
echo Mktime (13,15,23,6,7,2006);
?>
Date ($format, $ts)

This function formats the UNIX time label as a date string that can be read artificially. It is the most powerful function in the PHP date/Time API, and can be used in a series of correction values to convert the integer time label to the desired string format.

This function is applied to display the formatting time or date.

<?php
Format Current Date
Returns "13-sep-2005 01:16 PM"
echo Date ("D-m-y h:i A", Mktime ());
?>
strtotime ($STR)

This function converts an English date/time string that can be artificially read into a UNIX time label.

Apply this function to convert an nonstandard date/time string into a standard, compatible UNIX time label.

<?php
Returns 13-sep-05
echo Date ("D-m-y", Strtotime ("Today"));
Returns 14-sep-05
echo Date ("D-m-y", Strtotime ("Tomorrow"));
Returns 16-sep-05
echo Date ("D-m-y", Strtotime ("Today +3"));
?>
strftime ($format, $ts)

As defined by the previous setlocale () function, this function formats the UNIX time label as a date string that applies to the current environment.

Apply this function to establish a date string that is compatible with the current environment.

<?php
Set Locale to France (on Windows)
SetLocale (Lc_time, "Fra_fra");

Format month/day Names
As per locale setting
Returns "Septembre" and "mardi"

Echo strftime ("Month:%B");
echo strftime ("Day:%A");
?>
microtime ()

As defined by the previous setlocale () function, this function formats the UNIX time label as a date string that applies to the current environment.

Apply this function to establish a date string that is compatible with the current environment.

<?php
Get starting value
$start = Microtime ();

Run some code
For ($x =0 $x <1000; $x + +) {
$null = $x * $x;
}

Get ending value
$end = Microtime ();

Calculate time taken for code execution
echo "Elapsed time:". ($end-$start). " SEC ";
?>
gmmktime ($hour, $minute, $second, $month, $day, $year)

This function generates a UNIX time label from a series of date and time values expressed in GMT time. When you do not use a variable, it generates a UNIX time label for the current GMT instant time.

Use this function to obtain the UNIX time label for GMT Instant time.

<?php
Returns timestamp for 12:25:23 9-jul-2006
echo Gmmktime (12,25,23,7,9,2006);
?>
gmdate ($format, $ts)

This function formats the UNIX time label as a date string that can be read artificially. This date string is represented as GMT (not local time).

This function is applied when the time label is represented by GMT.

<?php
Format current date into GMT
Returns "13-sep-2005 08:32 AM"
Echo gmdate ("D-m-y h:i A", Mktime ());
?>
Date_default_timezone_set ($tz), Date_default_timezone_get ()

This function then all the date/time function calls set and restores the default time zone.

Note: This function is only valid in PHP 5.1+.

This function is a convenient shortcut for setting a time zone for future time operations.

<?php
Set TimeZone to UTC
Date_default_timezone_set (' UTC ');
?>