mktime() function in PHP

Definition:
The mktime() function returns the Unix timestamp for a specific date and time.

Unix timestamp means the number of seconds since January 1, 1970, 00:00:00 GMT.

Syntax:

mktime(hour, minute, second, month, day, year)

• hour (optional) – Default is current hour
• minute (optional) – Default is current minute
• second (optional) – Default is current second
• month (optional) – Default is current month
• day (optional) – Default is current day
• year (optional) – Default is current year

✅ If you don't provide values, it uses the current date and time.

Simple Examples:

1. Create a timestamp for a specific date and time

<?php
$timestamp = mktime(14, 30, 0, 4, 27, 2025);
echo $timestamp;
?>

🔹 This will give the timestamp for April 27, 2025, 2:30 PM.

2. Convert that timestamp into a readable date

<?php
$timestamp = mktime(14, 30, 0, 4, 27, 2025);
echo date("Y-m-d H:i:s", $timestamp);
?>

🔹 Output: 2025-04-27 14:30:00

3. Create today's date at midnight

<?php
$todayMidnight = mktime(0, 0, 0);
echo date("Y-m-d H:i:s", $todayMidnight);
?>

🔹 It will show today's date at 00:00:00.

4. Calculate a date 10 days in the future

<?php
$future = mktime(0, 0, 0, date("m"), date("d")+10, date("Y"));
echo date("Y-m-d", $future);
?>

🔹 Adds 10 days to today's date.

5. Using mktime to handle month overflow

<?php
$date = mktime(0, 0, 0, 13, 10, 2025);
echo date("Y-m-d", $date);
?>

🔹 Even though month 13 doesn't exist, PHP automatically adjusts it:
It will output 2026-01-10.

Why use mktime()?

• When you want to create a timestamp manually.
• When you want to add/subtract time easily (like "10 days from now").
• It auto-adjusts invalid dates (like month 13 or day 32).