function calculateWeeks(oFromDate, oToDate) {
		return Math.floor((oToDate.valueOf() - oFromDate.valueOf()) / iMillisecondsInWeek);
	}
Returns the rounded amount of weeks a given time frame.

@param {Date} oFromDate The beginning date of the time interval
@param {Date} oToDate The end date of the time interval
@returns {int} A rounded number which represents the amount of weeks in the given timer interval