Summary of php Common Date and Time Function Examples

In this paper, an example is given to describe the date and time functions commonly used in php. Share it for your reference, as follows:

Time stamp

I won't go into details about the timestamp. It is in the manual, that is, it can accurately represent a time point. When I do projects, I often use timestamps to represent data, which is more convenient. If it is saved as date-time data, it may be easier to display it, but if it is a certain year or month of this date, it is more troublesome.

<?php
echo time();// Return 1 A timestamp in seconds   : 1467968841
echo microtime(true);// Return 1 A timestamp in milliseconds   : 1467968841.4155
echo microtime();// Returns a timestamp with milliseconds and seconds   : 0.41553000 1467968841 Which is preceded by the fraction of milliseconds followed by the number of seconds 
?>

Timestamp formatting

1. date($format,$timestamp) Formatting a timestamp under the currently used time zone

2. gmdate($format,$timestamp) Specify the formatted timestamp under the UTC time zone, no matter what time zone the user uses

Concept of time zone: Time zone is set according to the place of time, China belongs to the East 8, so it is 8 hours faster than UTC (Greenwich Mean Time)

Gets and sets the time zone

date_default_timezone_get()// Gets the currently used time zone, which should be by default UTC
date_default_timezone_set( ' Asia/Shanghai')// Set the current time zone to Shanghai, Asia 

<?php
echo date("Y-m-d  Week N H:i:s a",$time);//2016-07-08  Week 5 10:44:26 am( Under the default time zone )
echo date("Y-m-d  Week N H:i:s a",0);//1970-01-01  Week 4 00:00:00( Under the default time zone )
echo gmdate("Y-m-d  Week N H:i:s a",0);//1970-01-01  Week 4 00:00:00( All in UTC Under time zone )
?>

Parse time format to timestamp

1. mktime (): Parse the established time format into a timestamp

<?php
echo mktime(19,15,0,7,8,2016);// Get 2016 Year 8 Month 7 Day 19 Hour 15 Points 0 Time stamp of seconds 
?>

2. strtotime (): Parses the date and time description of any English text into a timestamp

<?php
  echo strtotime("2016-7-8 19:15:0");// Get 2016 Year 8 Month 7 Day 19 Hour 15 Points 0 Time stamp of seconds 
  echo strtotime("now");// Get the current timestamp 
  echo strtotime("+1 day");// The current time is pushed back 1 Time stamp of days 
  echo strtotime("-1 day");// The current time is pushed forward 1 Time stamp of days 
?>

3. checkdate (): Detects whether the input date exists

<?php
var_dump(checkdate(2,29,2015));//2015 Year 2 Month 29 Day does not exist, so it is false
var_dump(checkdate(2,29,2016));//2016 Year 2 Month 29 Day exists, so it is true
?>

Case: Calculate the date difference between two dates

1. Use the timestamp to calculate

<?php
$day1 = "2016-7-8";
$day2 = "2016-7-1";
echo (strtotime($day1) - strtotime($day2))/(24 * 60 * 60);
?>

2. Calculate with DateTime class

<?php
$datetime1 = new DateTime('2016-7-8');
$datetime2 = new DateTime('2016-7-1');
$interval = $datetime2->diff($datetime1);
echo $interval->format('%R%a days');
?>

PS: Here are some time and date related tools for your reference:

Online date/day calculator:
http://tools.ofstack.com/jisuanqi/date_jisuanqi

Online date calculator/difference days calculator:
http://tools.ofstack.com/jisuanqi/datecalc

Online Date-Day Difference Calculator:
http://tools.ofstack.com/jisuanqi/onlinedatejsq

Unix timestamp (timestamp) conversion tool:
http://tools.ofstack.com/code/unixtime

For more readers interested in PHP related content, please check the topics on this site: "Summary of php Date and Time Usage", "Encyclopedia of PHP Array (Array) Operation Skills", "Introduction to PHP Basic Grammar", "Summary of PHP Operation and Operator Usage", "Introduction to php Object-Oriented Programming", "Introduction to php String (string) Usage", "Introduction to php+mysql Database Operation Skills" and "Summary of php Common Database Operation Skills"

I hope this article is helpful to everyone's PHP programming.