<script>
$('#input_text_date').persianDatepicker({
  calendar:{
    persian: {
      leapYearMode: 'astronomical'
    }
  }
});
</script>

The issue occurs because 1403 is a leap year in the Persian calendar. To fix this, you need to explicitly set leapYearMode: 'astronomical' in your configuration. The default setting (leapYearMode: 'algorithmic') uses a mathematical approximation that causes this one-day discrepancy for Persian leap years.