Question

new Date() takes an ordinal and returns a Date object.
What does Date() do, and how come it gives a different time?

>>> new Date(1329429600000)
Date {Fri Feb 17 2012 00:00:00 GMT+0200 (القدس Standard Time)}
>>> Date(1329429600000)
"Tue Mar 06 2012 15:29:58 GMT+0200 (Jerusalem Standard Time)"

Answer 1

From the specs:

When Date is called as a function rather than as a constructor, it returns a String representing the current time (UTC).

and:

When Date is called as part of a new expression, it is a constructor: it initialises the newly created object.

So, new Date(...) returns an object such that obj instanceof Date is true, whereas Date(...) basically returns the same as new Date().toString().