public final FEMDatetime moveZone(final int hours, final int minutes) throws IllegalStateException, IllegalArgumentException {
		if (!this.hasZone()) throw new IllegalStateException();
		if ((hours == 0) && (minutes == 0)) return this;
		if ((hours < -28) || (hours > 28)) throw new IllegalArgumentException();
		if ((minutes < -1680) || (minutes > 1680)) throw new IllegalArgumentException();
		return this._moveZone_((hours * 60) + minutes);
	}