如何在JavaScript中将日期差转换为数字

Question

I have designed a form which contains 3 fields From_date To_date No_of days i want to calculate the difference between from_date and to_date and the difference value will be shown in nu_of days. itried this code:

<script>
function difference()
{
var d1=document.getElementById("P1_FROM_DATE");
var d2=document.getElementById("P1_TO_DATE");
var d3=document.getElementB`yId("P1_NO_DAYS");
if(d2.value < d1.value)
{
alert("todate should not be less than from date");
d2.focus();
return false;
}
else
{
d3.value=(d2.value - d1.value)+1;
return true;
}
}
</script>

when this code executes and the condition satisfies then the no_of_days shows me NaN. So what is the solution please tell me.

Regards Sabyasachi

Answer 1

You are trying to use date-based methods on fields that only know about text. You'll need to use the Date class to convert these values from text and use those methods to perform your date arithmetic.

Good luck!

Answer 2

A generic formula. The date[x]-format has to be ISO (eg 'yyyy/mm/dd').

var diffDays = 
     Math.floor( (new Date([date1]) - new Date[date2]) / (1000*60*60*24) );

BTW, I suppose document.getElementById("P1_FROM_DATE") is an input field. In that case use document.getElementById("P1_FROM_DATE").value to avoid disappointments.