Javascript - variable previous business day

Question

I'm trying to create a drop down list that will automatically enter dates into text fields.

The option "LBD" currently returns yesterday's date, however, I'd like it to return the date of the last business day. So that if today is Monday, it would return Friday's date, if today is Tuesday it would return Monday's date. So on and so forth.

This is what I've got so far:

Javascript:

<script>
$(document).ready(function() {
$("#datetype option").filter(function() {
    return $(this).val() == $("#datepickstart").val();
    return $(this).val() == $("#datepickend").val();
}).attr('selected', true);
    var d = new Date();
var yesterday = (d.getMonth() + 1) + "/" + (d.getDate() - 1) + "/" + d.getFullYear();
var today = (d.getMonth() + 1) + "/" + d.getDate() + "/" + d.getFullYear();
var fdm = (d.getMonth() + 1) + '/01/' + d.getFullYear();
var fdy = '01/01/' + new Date().getFullYear();
$("#datetype").on("change", function() {
    var selectedVal = $(this).find("option:selected").attr("value");
    if (selectedVal == 'LBD') {
        $("#datepickstart").val((yesterday));
        $("#datepickend").val((yesterday));
    }
    if (selectedVal == 'MtD') {
        $("#datepickstart").val(fdm);
        $("#datepickend").val(today);
    }
    if (selectedVal == 'YtD') {
        $("#datepickstart").val(fdy);
        $("#datepickend").val(today);
    }
});
})
</script>

html:

<select id="datetype" name="datetype"> 
<option value="">Please select...</option> 
<option value="LBD">LBD</option> 
<option value="MtD">MtD</option> 
<option value="YtD">YtD</option> 
</select>

<input type="text" id="datepickstart" name="datepickstart" value="">
<input type="text" id="datepickend" name="datepickend" value="">

Answer 1

getDay() function is the key for your problem. I used @zzzzBov snippet for iterator. Below is my solution

step1:
   function isBusinessDay(date){
    var day = date.getDay();
    if(day == 0 || day == 6  ){
        return false;
    }
    return true;
    }


 step2:
    var date = new Date();
    while (!isBusinessDay(date)) { date.setDate(date.getDate() - 1) }

    console.log(date);//date always between monday to friday 

Hope this solves your problem. Happy coding!!