the Date object

the js Date object is marvelous
https://www.w3schools.com/jsref/jsref_ob­j_date.asp

but it's espruino implementation is very limited so far, to be specific, we can only read from the Date object once it has been created.

>t = new Date;
=Date { "ms": 949363947471.30676269531 }
>t.setHours(10);
Uncaught Error: Function "setHours" not found!
 at line 1 col 3

Im working on a time switch, I've been using date class all around, finding out that set-methods are not implemented made me (almost :P ) depressed

setDate()	Sets the day of the month of a date object
setFullYear()	Sets the year of a date object
setHours()	Sets the hour of a date object
setMilliseconds()	Sets the milliseconds of a date object
setMinutes()	Set the minutes of a date object
setMonth()	Sets the month of a date object
setSeconds()	Sets the seconds of a date object

Extending espruino's Date class would be extremely beneficial:
1) easy, date, time manipulation - clocks, timers, time switches
2) clock module wouldn't be necessary
3) if it's about memory, we can add set-methods and remove some of these:

• function Date.getTimezoneOffset - doesn't make sense on espruino since it's always 0;
  
• Date.getTime() is almost identical with Date.now() and Date.now() makes more sense on embedded
  
• Date.toUTCString is kind of useless when our timezoneOffset is always 0
  
  

Let me know what do you think of it!