public int setDuration() {
		// z ~ N(0,1) so transform
		double z = this.rng.nextGaussian();
		double x = z * this.sdStay + this.meanStay;
		int duration = ((int) x);
		if (duration > Constants.MINIMUM_STAY) {
			return duration;
		} else {
			return Constants.MINIMUM_STAY;
		}
	}