The **`filemtime()` function** is a built-in function in PHP. It returns the time when any specified file contents were last modified by the user.

# Syntax
```
filemtime($filename)
```
**`$filename`**: The file we want to check to determine when it was last modified. 

# Return value
This method returns a Unix timestamp denoting the last modified time. It returns `False` if the function does not execute successfully.

# Code
Let’s look at the code, which determines when the contents of `hello.txt` were last modified:




<?php
  
// Checking last modified time of file 
echo filemtime("hello.txt");
echo "\n";
// formatting the data in data and time format
echo "Checking last modified time of file: ".date("F d Y H:i:s.", 
                     filemtime("hello.txt"));
  
?>

The **`filemtime()` function** is a built-in function in PHP. It returns the time when any specified file contents were last modified by the user.

# Syntax
```
filemtime($filename)
```
**`＄filename`**: The file we want to check to determine when it was last modified. 

# Return value
This method returns a Unix timestamp denoting the last modified time. It returns `False` if the function does not execute successfully.

# Code
Let’s look at the code, which determines when the contents of `hello.txt` were last modified:




What is the filemtime() function in PHP?

The filemtime() function in PHP returns a Unix timestamp of the last modification time of a specified file.