PHP - How To Compare Dates?

Hi All,

I'm hoping someone can help as I've got myself in a muddle on some code.

Basically, the form has a date field (date moved in).

If the date entered is over 3 years old, all's ok

However, if the date entered is less than 3 years old, the user needs to complete a list field. The list field is essentially a repeater field with a date and address field.

If the user adds a date and address and this (plus the original date) is more than 3 years combined history - happy days!

If the user adds a date and address and they've still not hit 3 years history, then I need to increase the number of rows (this is handled by another function which works by incrementing a field on the form.

As it stands, it works until I need another field to appear i.e. they've entered the first date, then entered a date within the list/repeater field but still not got 3 years worth.

I think it's more or less there but seem to have muddled some of the logic (I think/hope!). A fresh pair of eyes would be great:

Here's my code:

function dateDiffInDays($date1, $date2) { 
    # Calulating the difference in timestamps 
    $diff = strtotime($date2) - strtotime($date1); 
      
    # 1 day = 24 hours 
    # 24 * 60 * 60 = 86400 seconds 
    return abs(round($diff / 86400)); 
} 

add_filter( 'gform_pre_render_2', 'applicant_2_previous_address_history' );
add_filter( 'gform_pre_validation_2', 'applicant_2_previous_address_history' );
function applicant_2_previous_address_history( $form ) {

	#get the value from the form date input d/m/Y so need to change
	$get_moved_in_date = rgpost( 'input_1' );
	if ( $get_moved_in_date ) {
		#convert the date format
		$moved_in_date = date_format(date_create_from_format('d/m/Y', $get_moved_in_date), 'd-m-Y'); 	
		#echo "New date format is: ".$moved_in_date. "<br/>"; 
	}
	
	#get todays date
	$today = date("d-m-Y");
	#echo "<h3>Today: ".$today."</h3>";
	
	#calculate the difference in days
	$dateDiff = dateDiffInDays($today, $moved_in_date); 	
	#printf("<p>Difference between two dates: " . $dateDiff . " Days</p>"); 	

	#check if we moved in less than 3 years ago
	if ( $dateDiff < 1095 ) {
		
		#less than 3 years, so need to loop through the list fields, compare dates and tally totals days
		if ( $days_sum < 1095 ) {
			
			# get the input from the list
			$list_values = rgpost( 'input_2' );
			$i = 0; #use this to get even rows only due to the way data is stored :(
			$sum = 0; #use this to increment the no. of rows in the list
			$previous = null; #use this to calc date difference between rows
			$days_sum = $dateDiff; #set the total number of days. Don't start at 0, start from current date - time at current residence
			if ( $list_values ) {
				foreach ( $list_values as $key => $value ){
					#get even rows only
					if($i%2 == 0){
						
						#$sum = $sum + 1; #increment our rows
						
						if ( $value ) {
							#convert the date format
							$additional_date = date_format(date_create_from_format('d/m/Y', $value), 'd-m-Y');
							#echo "<h3>Date: ".$additional_date."</h3>";
						}			
								
						if ( $previous !== null ){ # if it's null, we're in the first loop
						
							#convert the date format
							$previous_date = date_format(date_create_from_format('d/m/Y', $previous), 'd-m-Y');
							
							$dateDiff2 = dateDiffInDays($additional_date, $previous_date); 	
							printf("<p>Next Iteration Difference between " . $additional_date . " and " . $previous_date . " is: " . $dateDiff2 . " Days</p>"); 	
							
							$days_sum = $days_sum + $dateDiff2;
							
						} else {
							
							#convert the date format
							$dateDiff1 = dateDiffInDays($additional_date, $moved_in_date); 	
							printf("<p>1st Iteration Difference between " . $additional_date . " and " . $moved_in_date . " is: " . $dateDiff1 . " Days</p>"); 	
							
							$days_sum = $days_sum + $dateDiff1;
							
						}
						
						$previous = $value; # set the current value, so it will be saved for the next iteration
			
					}
					$i++;
				} #end foreach $list_values
			} #endif $list_values
			$sum = $sum + 1; #increment our rows
			echo "<p>Total no of days = " .$days_sum.'</p>';
			
		} #endif $days_sum < 1095	
	
		echo '<p>Not enough days so loop through list</p>';
		$flag = 'true';
		
	} else {
		
		echo '<p>Were ok!</p>';
		$flag = 'false';	
		
	} #endif $dateDiff < 1095



	/*
	if ( $dateDiff < 1095 ) {
		$value = 'yes';
	} else {
		$value = 'no';	
	}	
	*/

	#we moved in less than 3 years ago, so get history
	if ( $flag == 'false' ) {		
        return $form;
    } 

    foreach ( $form['fields'] as &$field ) {
        if ( $field->id == 2 ) {
            $field->isRequired = true;
        }
		echo "<p>The sum of array element is = " .$sum.'</p>';
		if ( $field->id == 3 ) {
			$_POST['input_3'] = $sum;
		}
		
    }

    return $form;
	
}

Thanks