SimpleRectangleEngine sre = new SimpleRectangleEngine();
TimeOffset shiftBegin = new TimeOffset(7, 0);
TimeOffset shiftEnd = new TimeOffset(20, 0);
TimeScaler scaler = new TimeScalerTraditional(shiftBegin.getHours(), shiftEnd.getHours(), 0.25f);
scaler.setMinHourHeight(25);
ruler.setScaler(scaler);
ruler.setShiftBegin(shiftBegin.getMilliseconds());
ruler.setShiftEnd(shiftEnd.getMilliseconds());
ruler.setFont(rulerLabel.getFont());