How to set Date/Time in salesforce using javascript

Question

I am updating the record in the javascript while clicking on custom button. I have custom date/time field Approved_Date__c. I need to update that fields also using javascript. How can I assign current date/time to Approved_Date__c field?

I tried like

set("Approved_Date__c",NOW());
set("Approved_Date__c",Date.NOW());
set("Approved_Date__c",Date.Time());

but i am getting:

A problem with onclick javascript for this button or link was encountered. Now not defined.

I tried like this also

jpt.Approved_Date__c=new Date().toLocaleString();

it's showing as:

{faultcode:'soapenvClient', faultstring:''3/21/2016, 3:05:33 PM' is notavalid value for the type xsd:dateTime',}

Answer 1

I got solution for this. I tried like this..

jpt.Approved_Date__c=new Date().toISOString();

Answer 2

I believe you are in the right direction. The only thing I see missing is the {! expression }.

I believe the first approach will work for you.

set("Approved_Date__c",{! NOW() });