Date and time functions for PHP

1, Mktime () function:

The UNIX timestamp is returned based on the batch parameter, which needs to be formatted with the date () function to output the date and time.

Example: Use the Mktime () function to get the current time of the system

<?php
echo "Mktime function return value:". Mktime (). <br/> ";
echo "Current date time is:". Date ("Y-m-d h:i:s", Mktime ());
?>

2, Time () function: Returns the current UNIX timestamp

Cases:

<?php
echo "The return value of the time function:". Time (). <br/> ";
echo "Current time is:". Date ("Y-m-d h:i:s", Mktime ());
?>

3, Date () function: Gets the current date time

Date time can be exported in the format specified

Cases:

$time 1=date ("y-m-d h:i:s"); Get current time

4, GETDATE () function:

Gets information about the specified part of the date, and returns the date and time information in the array form.

Example: Show today is the first day of the year

<?php
$arr =getdate ();
echo $arr [' Year ']. -". $arr [' mon ']." -". $arr [' Mday ']." <br/> ";  Output the current date
echo $arr [' hours ']. -". $arr [' minutes ']." -". $arr [' seconds ']." ". $arr [' Weekday ']; Output the current time information
echo "<br/>";
echo "Today is the first of the year". $arr [' yday ']. "Day"; Output today is the first day of the year
?>

5, Checkdate () function:

The Checkdate () function is a built-in date check function in PHP

The syntax is as follows:

BOOL Checkdate (int month,int day, int)

Where the valid value for month is the maximum number of days of the month for 1-12,day, and the valid value for year is 1-366

Cases:

<?php

$month = 2;
$day 1=29;
$day 2=30;
Var_dump (Checkdate ($month, $day 1, $year)); Returns True, February is only 29 days
echo "<br/>";
Var_dump (Checkdate ($month, $day 2, $year)); return False, February is only 29 days
?>

6, Strtotime () function:

function: Resolves a string of dates into a timestamp to compare the size of two times.

Time in PHP can not be directly compared, you need to first parse the time into a timestamp form, and then compare.

Cases:

<?php
$time 1=date ("y-m-d h:i:s"); Get current time
$time 2 = "2019-2-6 12:30:00";
if (Strtotime ($time 1)-strtotime ($time 2) >0) {//Compare two time
   echo "\ $time 1 earlier than \ $time 2";
}else{
   echo "\ $time 1 late than \ $time 2";
}
?>

Example: Using the Strtotime () function to develop a countdown program

<?php
$time 1=strtotime (Date ("y-m-d h:i:s")); Get current time
$time 2=strtotime ("2017-1-1"); New Year's Time
$sub =ceil (($time 2-$time 1)/86400); (60 seconds *60 * 24 hours)/day
echo "From New Year's Day and <font color= ' red ' > $sub </font> days! ";
?>