Detailed explanation of php checkdate, getdate and other date and time function operations_PHP tutorial

checkdate($month,$date,$year)
This function returns true if the applied value constitutes a valid date. For example, for the error date February 31, 2005, this function returns false.
This function can be used to check a date and make it valid before it is used in calculations or saved in the database.

Copy code The code is as follows:

// returns false
echo checkdate(2 ,30,2005) ? "valid" : "invalid";
// returns true
echo checkdate(4,6,2010) ? "valid" : "invalid";
?>

　getdate($ts)
　With no arguments, this function returns the current date and time in a combined array. Each element in the array represents a specific component of the date/time value. An optional time stamp argument can be submitted to the function to obtain a date/time value corresponding to the time stamp.
Apply this function to obtain a series of discrete, easily separable date/time values.

Copy code The code is as follows:

// 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)
This function does the opposite of getdate(): it generates a UNIX time stamp from a series of date and time values ​​(GMT time 1970 1 The number of seconds that have elapsed since the 1st of the month). When no arguments are used, it generates a UNIX time stamp of the current time.
Use this function to obtain the UNIX time label of the real-time time. Such timestamps are commonly used in many databases and programming languages.

Copy code The code is as follows:

// returns timestamp for 13:15:23 7-Jun- 2006
echo mktime(13,15,23,6,7,2006);
?>

　date($format, $ts)
This function formats a UNIX time stamp into a human-readable date string. It is the most powerful function in the PHP date/time API and can be used to convert integer time labels into the required string format in a series of correction values.
Apply this function when formatting time or date for display.

Copy code The code is as follows:

// format current date
// returns "13-Sep-2005 01:16 PM"
echo date("d-M-Y h:i A", mktime());
?>

　strtotime( $str)
This function converts a human-readable English date/time string into a UNIX time tag.
Apply this function to convert a non-standardized date/time string into a standard, compatible UNIX time tag.

Copy code The code is as follows:

// 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 days"));
?>

strftime($format,$ ts)
As defined by the previous setlocale() function, this function formats the UNIX time stamp into a date string suitable for the current environment.
Apply this function to create a date string compatible with the current environment.

Copy code The code is as follows:

// 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 before As defined by the setlocale() function, this function formats a UNIX time stamp into a date string appropriate for the current environment.
Apply this function to create a date string compatible with the current environment.

Copy code The code is as follows:

// 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 stamp from a series of date and time values ​​expressed in GMT time. When no arguments are used, it generates a UNIX time stamp of the current GMT time.
Use this function to obtain the UNIX time label of GMT real-time time.

Copy code The code is as follows:

// returns timestamp for 12:25:23 9 -Jul-2006
echo gmmktime(12,25,23,7,9,2006);
?>

　gmdate($format, $ts)
This function formats a UNIX time stamp into a human-readable date string. This date string is expressed in GMT (not local time).
This function is applied when GMT is used to represent the time label.

Copy code The code is as follows:

// 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()
All date/time function calls after this function set and restore the default time zone.
Note: This function is only valid in PHP 5.1+.
This function is a convenient shortcut for setting the time zone for future time operations.

Copy code The code is as follows:

// set timezone to UTC
date_default_timezone_set( 'UTC');
?>

http://www.bkjia.com/PHPjc/321327.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/321327.htmlTechArticlecheckdate($month,$date,$year) This function returns if the applied value constitutes a valid date is true. For example, for the error date February 31, 2005, this function returns false. On date...