Hi Susan,

   Kindly Find the Below Example:

1. Event Start Date
2. Event Completion Date
3. Event Deadline

-----

• Event Start Date:

Start from today

• Event Completion Date:

Start from selected start date.

• Event Deadline:

From today and event start date

//*****Date Validation _____________________________
    var d = new Date();
    var year=d.getFullYear();
    var month=("0"+(d.getMonth()+1)).slice(-2);
    var day=("0"+d.getDate()).slice(-2);
//--------
//Event Date
    var v_Start_Date_maxDate=((parseInt(year)+5)+"-"+month+"-"+day);
    var v_Start_Date_minDate=(year+"-"+month+"-"+day);
    $('.v_Start_Date input').attr('max',v_Start_Date_maxDate);
    $('.v_Start_Date input').attr('min',v_Start_Date_minDate);
     
$('.v_Start_Date input').change(function(){
   if($(this).val()!='')
   {
    $('.v_Completion_Date input').val('');
    var com_d=$(this).val();
    var com_year=com_d.slice(-4);
    var com_month=com_d.slice(3, 5);
    var com_day=com_d.slice(0, 2);
    var v_Completion_Date_maxDate=((parseInt(com_year)+10)+"-"+com_month+"-"+com_day);
    var v_Completion_Date_minDate=(com_year+"-"+com_month+"-"+com_day);
    $('.v_Completion_Date input').attr('max',v_Completion_Date_maxDate);
    $('.v_Completion_Date input').attr('min',v_Completion_Date_minDate);

    $('.v_Registration_Deadline_of_Conference_Event input').val('');
    var v_Registration_Deadline_maxDate=v_Completion_Date_minDate;
    var v_Registration_Deadline_minDate=v_Start_Date_minDate;
    $('.v_Registration_Deadline_of_Conference_Event input').attr('max',v_Registration_Deadline_maxDate);
    $('.v_Registration_Deadline_of_Conference_Event input').attr('min',v_Registration_Deadline_minDate);
   }
    else
    {
     $('.v_Completion_Date input').val('');
     $('.v_Registration_Deadline_of_Conference_Event input').val('');
    }
});

$('.v_Completion_Date input').change(function(){
    $('.v_Registration_Deadline_of_Conference_Event input').val('');
});

warm regards,

Mohamed Farid