How to count revisited customer ( more than 1 time) in laravel using query builder?

I need to count revisited customer in one month. It means need to count customer_id has more than one entry in table within a month.

My query is showing only the total customer.

$count_customer_current_month = DB::table("customer_entry")->whereRaw('MONTH(date) = ?', 
                                [$currentMonth])->count();

via Chebli Mohamed