[jQuery] What is +new Date; in the function now()?

[jQuery] What is +new Date; in the function now()?


I'm not familiar with the JavaScript syntax of "+new" in the now()
function in jQuery 1.2.5. Would you explain the plus (+) operator? How
does it work? What does it mean?
function now(){
return +new Date;
}
Is it the same as the following?
function now(){
return new Date();
}