Yeah, idea is nice, but I also don’t think this is really something you should spend time on. Fortunately it is only visible when no map is downloaded but I think it is a stupid thing to do.
It are also not snowflakes but stars.

Looking at this piece of code I think it will be on from december 17 until december 31.

	    private static boolean isChristmas() {
	        Calendar c = new GregorianCalendar();
	        c.setTime(new Date());
	        return c.get(Calendar.DAY_OF_YEAR) > 350;
	    }

No, it is not about christmas. Not at all.