This is standard javascript. Not node specific
When calling a constructor with new
the parenthesis are optional if it takes no arguments
function MyObject () {}
new MyObject();
new MyObject; // these both create an object
The +
is just a shorthand way of casting to a number.
Its the unary plus operator simmilar to the unary minus operator in -5
+'123' === 123 // true
In the case of +new Date
this casts a Date object to a number or the current number of milliseconds since the unix epoch. Result is the same as date.getTime()
.