Date time and Mathematical function in PHP:-

Date time is the most important function of today programming because we always create logic for the expiration date, total duration, age calculation, time calculation

PHP Provide in-built function for date and time:-

1)  date():-  it is a predefined function that provides the current date and time using different parameters.

echo date('d')."<br>";  //return day index

echo date('m')."<br>"; //return month index

echo date('y')."<br>";  // return year last 2 digit

echo date('D')."<br>"; //return day name

echo date('M')."<br>"; // return Month name

echo date('Y')."<br>";  //return complete year

echo date('d-m-y')."<br>";  //return complete date

date_default_timezone_set("Asia/Kolkata");   //change time zone 

echo date('h')."<br>";   //return hours

echo date('i')."<br>";  //return minuts

echo date('s')."<br>";  //return second

echo date('h-i-s')."<br>";  //return time

echo time();   //return time in second from 1 jan 1970

echo(date("Y-m-d h-i-s",time()));   //return complete date and time

2) strtotime():-  It is used to convert date to string:-

echo(strtotime("now") . "<br>");  //convert current time to string

echo(strtotime("3 October 2005") . "<br>");  //convert 3 oct 2005 time to string

echo(strtotime("+5 hours") . "<br>");  //increase five house in current time

echo(strtotime("+1 week") . "<br>");   //display 1 week  after time

echo(strtotime("+1 week 3 days 7 hours 5 seconds") . "<br>");  // 

echo(strtotime("next Monday") . "<br>");

echo(strtotime("last Sunday"));

Mathematical function in PHP:-

This function is used to perform the mathematical operation in PHP

<?php

echo abs(-2)."<br>";  //negative value to positive

echo pi(). "<br>";   // return pi 3.14

echo sqrt(5)."<br>";   //return square root

echo pow(5, 3)."<br>";  //return power of any base and exponent

echo sin(45)."<br>";   // these all are Trigonometry

 function

echo cos(45)."<br>";

echo tan(45)."<br>";

echo cosec(45)."<br>";

echo sec(45)."<br>";

echo cot(45)."<br>";

echo log(3)."<br>";

echo ceil(3.2)."<br>";  // highest integer value

echo floor(3.9)."<br>"; // lowest integer value

?>