Check validation if date is < 3 months

You are putting your date into an array and then comparing it to a timestamp. Why are you doing that?

Assuming $current_employee->emp_dtentry is a Unix timestamp:

if ($current_employee->emp_dtentry < strtotime('+3 months')) {

If it is not a Unix timestamp and is a valid date format you can do:

if (strtotime($current_employee->emp_dtentry) < strtotime('+3 months')) {

If it is not a valid date format you would need to use DateTime::createFromFormat() to parse the date and then do your comparison. That is easier to do with DateTime objects throughout.

// see manual format options$empdtEntry = DateTime::createFromFormat('<format goes here>', ($current_employee->emp_dtentry); $current_employee->emp_dtentry);$threeMonthsFromNow = new DateTime(+3 months);if ($empdtEntry < $threeMonthsFromNow ) {

As you are redirecting, your echo won't work. Either flash your javascript or use javascript there to redirect too.

Using flash:

 $dateEntry = $current_employee->emp_dtentry; if ($dateEntry < strtotime('+3 months')) {    $this->session->set_flashdata("javascript", "<script>alert('you don't have the right to access this menu')</script>");    redirect('new_leave'); }

Then within the new_leave view check it if exists and echo it:

if($this->session->flashdata('javascript')){    echo $this->session->flashdata('javascript');}

Or using javascript do it as below:

 $dateEntry = $current_employee->emp_dtentry; if ($dateEntry < strtotime('+3 months')) {    echo "<script>alert('you don't have the right to access this menu'); window.location.href='new_leave';</script>"; }