void test_time_axis() {

  TTimeStamp dateLo(2012, 01, 01, 00, 00, 00);
  TTimeStamp dateHi(2012, 06, 02, 00, 00, 00);
  time_t numDays = ((dateHi.GetSec() - dateLo.GetSec()) / (24 * 60 * 60)) + 1;

  TTimeStamp a(dateLo);
  TTimeStamp b(dateHi);
  // Careful with this magic. It centers the bins on the days.
  b.SetSec(b.GetSec() + (24 * 60 * 60));
  a.SetSec(a.GetSec() - (60 * 60));
  b.SetSec(b.GetSec() - (60 * 60));
  TH1F* hTest = new TH1F("", "", numDays, a.GetSec(), b.GetSec());

  for (size_t i = 0; i != numDays; ++i) {
    hTest->SetBinContent(i + 1, i + 1);
  }

  hTest->SetLineWidth(2);
  hTest->GetXaxis()->SetTimeDisplay(1);
  hTest->GetXaxis()->SetTimeFormat("%d/%m");
  hTest->GetXaxis()->SetTimeOffset(0, "gmt");

  TCanvas* canvas = new TCanvas("canvas", "Canvas", 10, 10, 1800, 1400);
  hTest->Draw();
  canvas->Print("test_time_axis.png");

}