Two color progress bar or somesuch

using System;
using System.Drawing;
using System.Windows.Forms;

class TimeLine : Panel {
private TimeSpan mStart = new TimeSpan(8, 0, 0); // Default: 8am
private TimeSpan mEnd = new TimeSpan(16,0,0); // Default: 4pm
public TimeSpan TimeStart {
get { return mStart; }
set { mStart = value; Invalidate(); }
}
public TimeSpan TimeEnd {
get { return mEnd; }
set { mEnd = value; Invalidate(); }
}
protected override void OnPaint(PaintEventArgs e) {
// Paint time line, 6am to 6pm. Calculate pixel positions
long totalTick = new TimeSpan(12, 0, 0).Ticks;
long startTick = mStart.Ticks - new TimeSpan(6, 0, 0).Ticks;
if (startTick < 0) startTick = 0;
long endTick = mEnd.Ticks - new TimeSpan(6, 0, 0).Ticks;
if (endTick > totalTick) endTick = totalTick;
if (startTick > endTick) startTick = endTick;
int w = this.Width - 10; // 5 pixel space and start and end
int sx = 5 + (int)(w * startTick / totalTick);
int ex = 5 + (int)(w * endTick / totalTick);
// Draw it
Pen gpen = new Pen(Color.LightGreen, 3);
Pen rpen = new Pen(Color.Red, 3);
int y = this.Height / 2;
e.Graphics.DrawLine(gpen, 5, y, sx, y);
e.Graphics.DrawLine(rpen, sx, y, ex, y);
e.Graphics.DrawLine(gpen, ex, y, w + 5, y);
// Allow app to paint of top of this:
base.OnPaint(e);
}
}