PHP - How to use $timestamp to check if today is Monday or 1st of the month?

In PHP, you can use the date() function with a timestamp to check if today is Monday or the 1st of the month. The date() function formats a timestamp based on the specified format string.

The timestamp parameter is optional and defaults to the current time if not provided.

Syntax

date(format, timestamp)

Parameters

• format − Required. Specifies the format of the outputted date string
• timestamp − Optional. Specifies a Unix timestamp. Default is the current date and time

Example

Here's how to check if a given timestamp represents Monday or the 1st day of the month ?

<?php
// Example timestamp for demonstration (January 1st, 2024 - Monday)
$timestamp = mktime(0, 0, 0, 1, 1, 2024);

// Check if it's the first day of the month
if(date('j', $timestamp) === '1') {
    echo "It is the first day of the month<br>";
}

// Check if it's Monday
if(date('D', $timestamp) === 'Mon') {
    echo "It is Monday<br>";
}

// Display the actual date for reference
echo "Date: " . date('Y-m-d (D)', $timestamp) . "<br>";
?>

The output of the above code is ?

It is the first day of the month
It is Monday
Date: 2024-01-01 (Mon)

Format Characters

Using Current Time

To check the current date without specifying a timestamp ?

<?php
// Check current date (no timestamp parameter)
if(date('j') === '1') {
    echo "Today is the first day of the month<br>";
} else {
    echo "Today is not the first day of the month<br>";
}

if(date('D') === 'Mon') {
    echo "Today is Monday<br>";
} else {
    echo "Today is not Monday<br>";
}

echo "Current date: " . date('Y-m-d (D)') . "<br>";
?>

Conclusion

Use date('j', $timestamp) to check if it's the 1st day of the month and date('D', $timestamp) to check if it's Monday. Omit the timestamp parameter to check the current date.