that means: Year,Month (0=January),Date,Hours,Minutes,Seconds,Milliseconds. Don't [I]use[/I] the red square brackets, I use them only to point out here the fact that the square bracketed values are optional. If no value, 0 (or 1 in case of date) is their default.
If no arguments at all, the new Date() object will return the precise date when the method is called (the [I]"now"[/I] moment)