I get the following error in my console log. What am I doing wrong?

   p {_isAMomentObject: true, _i: '', _f: 'DD-MM-YYYY HH:mm:ss', _isUTC: false, _pf: {…}, …}
_d: Invalid Date {}
_f: "DD-MM-YYYY HH:mm:ss"
_i: ""
_isAMomentObject: true
_isUTC: false
_isValid: false
_locale: P

data.planning_deadline has the following format of date values stored 21-10-2021

Below code:

rowCallback: function ( row, data ) {
                var daysleft = moment(data.planning_deadline, 'DD-MM-YYYY HH:mm:ss');
                console.log(daysleft);
                var now = moment(); 
                
                 if ( daysleft.diff(now, 'days') <= 0 && data.planning_deadline != "" && data.planning_afgehandeld == 0 ){
                 $('td:eq(0)', row).css('background-color', ' rgba(255, 0, 0, 0.2)');
                 }