form_month()
function form_month(string $name, ?string $value = null, array $attributes = []): string
Description
Generates an HTML month input field with a native browser month picker. The input allows users to select a month and year, submitting data in YYYY-MM format.
Browser Display vs Submitted Format: Browsers display months according to user locale, but always submit in consistent YYYY-MM format that your PHP code can rely on.
Demonstration
Below is the native HTML5 month input rendered by form_month():
Parameters
| Parameter | Type | Description | Default | Required |
|---|
| $name |
string |
The name attribute for the input element |
N/A |
Yes |
| $value |
string|null |
The month value in YYYY-MM format (zero-padded) |
null |
No |
| $attributes |
array |
Additional HTML attributes as key-value pairs |
[] |
No |
Return Value
| Type | Description |
|---|
| string | The generated HTML month input element |
Understanding the Attributes Array
The $attributes array accepts standard HTML input attributes. For month inputs, these are particularly useful:
| Attribute | Description | Example Value |
|---|
min |
Earliest selectable month (YYYY-MM) |
'2025-01' |
max |
Latest selectable month (YYYY-MM) |
'2025-12' |
required |
Field must have a value |
true |
readonly |
Prevent user editing |
true |
disabled |
Disable the input |
true |
Boolean Attributes: Pass true for boolean attributes like required, readonly, or disabled. This generates clean HTML5 syntax: <input required>
Month Format: Months must be zero-padded: 01 for January, 12 for December. The format is always YYYY-MM.
Example #1: Basic Month Input
public function create(): void {
$data['form_location'] = BASE_URL . 'reports/create';
$this->view('report_form', $data);
}
View file:
<?php
echo form_open($form_location);
echo form_label('Report Month');
echo form_month('report_month');
echo form_submit('submit', 'Continue');
echo form_close();
?>
Output:
<input type="month" name="report_month">
Example #2: Month Input with Default Current Month
public function create(): void {
$data['billing_month'] = post('billing_month', true);
// Default to current month if not submitted
if ($data['billing_month'] === '') {
$data['billing_month'] = date('Y-m');
}
$data['form_location'] = BASE_URL . 'invoices/create';
$this->view('invoice_form', $data);
}
View file:
<?php
echo form_open($form_location);
echo form_label('Billing Month');
echo form_month('billing_month', $billing_month);
echo form_submit('submit', 'Create Invoice');
echo form_close();
?>
The example above shows setting the current month as a default value using date('Y-m') which automatically zero-pads the month.
Form Repopulation: After validation errors, use post('field_name', true) in the controller to fetch the submitted value. This returns an empty string if no value was submitted.
Example #3: Financial Reporting System
public function generate_report(): void {
$data['report_month'] = post('report_month', true);
// Set constraints: can only generate reports for past 12 months
$current_date = new DateTime();
$data['max_month'] = $current_date->format('Y-m');
$min_date = clone $current_date;
$min_date->modify('-12 months');
$data['min_month'] = $min_date->format('Y-m');
$data['form_location'] = BASE_URL . 'reports/submit';
$this->view('report_form', $data);
}
public function submit(): void {
$this->validation->set_rules('report_month', 'report month', 'required|valid_month');
if ($this->validation->run() === true) {
$report_month = post('report_month', true);
// Generate report for selected month
$report_data = $this->generate_monthly_data($report_month);
set_flashdata('Report generated for ' . $report_month);
redirect('reports/view/' . $report_month);
} else {
$this->generate_report();
}
}
private function generate_monthly_data(string $month): array {
// Parse month: 2025-12 becomes year=2025, month=12
list($year, $month_num) = explode('-', $month);
$sql = "SELECT * FROM sales
WHERE YEAR(sale_date) = :year
AND MONTH(sale_date) = :month";
return $this->db->query_bind($sql, [
'year' => $year,
'month' => $month_num
], 'array');
}
View file:
<?php
echo form_open($form_location);
echo form_label('Report Month');
$attrs = [
'min' => $min_month,
'max' => $max_month,
'required' => true
];
echo form_month('report_month', $report_month, $attrs);
echo form_submit('submit', 'Generate Report');
echo form_close();
?>
The example above demonstrates a financial reporting system where users can only generate reports for the past 12 months. The DateTime object makes month calculations clean and reliable.
Example #4: Create/Update Pattern for Subscriptions
public function create(): void {
$update_id = segment(3, 'int');
if ($update_id > 0 && REQUEST_TYPE === 'GET') {
// Editing existing record
$record = $this->db->get_where($update_id, 'subscriptions');
$data['customer_name'] = $record->customer_name;
$data['billing_month'] = $record->billing_month; // Already in YYYY-MM format
} else {
// New record or validation error
$data['customer_name'] = post('customer_name', true);
$data['billing_month'] = post('billing_month', true);
}
$data['form_location'] = BASE_URL . 'subscriptions/submit/' . $update_id;
$this->view('subscription_form', $data);
}
public function submit(): void {
$update_id = segment(3, 'int');
$this->validation->set_rules('customer_name', 'customer name', 'required');
$this->validation->set_rules('billing_month', 'billing month', 'required|valid_month');
if ($this->validation->run() === true) {
$data['customer_name'] = post('customer_name', true);
$data['billing_month'] = post('billing_month', true);
if ($update_id > 0) {
$this->db->update($update_id, $data, 'subscriptions');
set_flashdata('Subscription updated successfully');
} else {
$this->db->insert($data, 'subscriptions');
set_flashdata('Subscription created successfully');
}
redirect('subscriptions/manage');
} else {
$this->create();
}
}
View file:
<?php
echo form_open($form_location);
echo form_label('Customer Name');
echo form_input('customer_name', $customer_name, ['required' => true]);
echo form_label('Billing Month');
echo form_month('billing_month', $billing_month, ['required' => true]);
echo form_submit('submit', 'Save Subscription');
echo form_close();
?>
The example above demonstrates the standard create/update pattern with a month field. No conversion is needed between the form and database because the YYYY-MM format can be stored directly in a VARCHAR column.
Type-Casting Segments: Always use segment(3, 'int') when expecting numeric IDs. This prevents type-related bugs and improves code clarity.
Example #5: Budget Planning with Future Months
public function plan_budget(): void {
$data['budget_month'] = post('budget_month', true);
// Allow planning for next 12 months
$current_date = new DateTime();
$data['min_month'] = $current_date->format('Y-m');
$max_date = clone $current_date;
$max_date->modify('+12 months');
$data['max_month'] = $max_date->format('Y-m');
$data['form_location'] = BASE_URL . 'budgets/submit';
$this->view('budget_form', $data);
}
View file:
<?php
echo form_open($form_location);
echo form_label('Budget Month');
$attrs = [
'min' => $min_month,
'max' => $max_month,
'required' => true
];
echo form_month('budget_month', $budget_month, $attrs);
echo form_label('Budget Amount');
echo form_number('budget_amount', $budget_amount, ['required' => true, 'min' => 0, 'step' => 0.01]);
echo form_submit('submit', 'Save Budget');
echo form_close();
?>
The example above demonstrates budget planning where users can create budgets for the next 12 months. The DateTime object makes month calculations straightforward.
Database Storage: Store month values in a VARCHAR(7) column in YYYY-MM format. This keeps the data human-readable and makes it easy to query by year or month using string functions or database date functions.