Date and Time Functions in PHP

The date() function used to converts a timestamp to readable date and time format.

	Syntax
<?php
  date(format,timestamp);
?>
format : which format we want our output.
timestamp : (optional).if not given, It will take the current date time  on the server.

What is a Timestamp?

Number of Seconds between Current time and 1^st January 1970 00:00:00. It is depends on the default time zone.

The following code shows, how to display the current timestamp.

	Timestamp

<?php
  echo time();
?>

Get current Date and Change Formats :

<?php  
  #Get Current Date
  $current_date=date("d-m-Y");
  echo $current_date; 

  #Change date format
  $simple_date="2020-12-31";
  echo date("Y",strtotime($simple_date));   # 2020
  echo date("d-m-Y",strtotime($simple_date)); # 31-12-2020
  echo date("Y M d",strtotime($simple_date)); # 2020 Dec 31
  echo date("D Y M",strtotime($simple_date)); # Thu 2020 Dec 
  
  #Convert 'yyyy-mm-dd' to 'dd-mm-yyyy'
  $date1="2020-12-31";
  $format_date=date("d-m-Y",strtotime($date1));
  echo $format_date; # 31-12-2020
  
  #Convert 'dd-mm-yyyy' to 'yyyy-mm-dd'
  $date2="31-12-2020";
  $format_date=date("Y-m-d",strtotime($date2));
  echo $format_date; # 2020-12-31
?>

d - Day of the Month (01 to 31)
D - Day Abbrivation (Mon tp Sun)
m - Month (01 to 12)
M - First 3 letters of Month Name (Jan to Dec)
F - Month name (January to December)
y - Year (94)
Y - Year (1994)

Get current Time :

<?php 
  #set the timezone Programmatically
  date_default_timezone_set('Asia/Kolkata');
  
  #Get Current Time:
  $current_time=date("h:i:s a");
  echo $current_time; 
?>

H - 24 Hour Format ( 01 to 24)
h - 12 Hour Format ( 01 to 12)
i - Minutes ( 00 to 59)
s - Seconds ( 00 to 59)
a - am or pm
A - AM or PM