How can I change the value of the checkbox if checked?

The jsfiddle below does what you want by switching the values ​​from 0 to 1 (or vice versa) depending on whether they are checked or not.

There are log demos for each loop, you don't actually need to do this. By default, oncheck's .checked property is already set to true or false, so you only need to use this property.

HTML

<input type="checkbox" name="Semi Annual" id="1" value="0">
        Semi Annual <br>
<input type="checkbox" name="Quaterly" id="2" value="0">
        Quaterly <br>
<input type="checkbox" name="Monthly" id="3" value="0">
        Monthly <br>

JS

$('input[type="checkbox"]').change(function(){

    // Changes value to 1 or 0 depending on whether it is checked or not
    if(this.value == 0){
        this.value = 1;
    }
    else{
        this.value = 0;  
    }

    // Log shows the value of each checkbox and also that the .checked property does the same thing by default
    $('input[type="checkbox"]').each(function(index, element){
        if(element.checked){
            console.log(this.name + ' has value of ' + this.value);
            console.log(this.name + ' is checked');   
        }
        else{
            console.log(this.name + ' has value of ' + this.value);
            console.log(this.name + ' is not checked');             
        }
    });
});