void demoTimeAxis()
{

  TTimeStamp startTime(2010,07,21,13,0,0, 0, kTRUE);
  TTimeStamp stopTime1(2010,07,21,15,0,0, 0, kTRUE);
  TTimeStamp stopTime2(2011,07,21,13,0,0, 0, kTRUE);

  assert( startTime.GetSec() == 1279717200 ); // startTime.GetSec() is "epoch" of 21/07/2010 13:00:00 GMT 

  cout << "Start time: " << startTime.AsString() << endl;
  cout << "Stop time1: " << stopTime1.AsString() << endl;
  cout << "Stop time2: " << stopTime2.AsString() << endl;


  TH1F *timeHist1  = new TH1F("timeHist1" ,"foo",100, startTime.GetSec(), stopTime1.GetSec() );
  TH1F *timeHist1a = new TH1F("timeHist1a","foo",100, startTime.GetSec(), stopTime1.GetSec() );
  TH1F *timeHist1b = new TH1F("timeHist1b","foo",100, startTime.GetSec(), stopTime1.GetSec() );
  TH1F *timeHist1c = new TH1F("timeHist1c","foo",100, startTime.GetSec(), stopTime1.GetSec() );
  TH1F *timeHist2  = new TH1F("timeHist2" ,"foo",100, startTime.GetSec(), stopTime2.GetSec() );
 
  // this does not do the right thing
  gStyle->SetTimeOffset(0);


  c = new TCanvas("t1","t1");
  c->Divide(2,2);
  
  c->cd(1);
  timeHist1->GetXaxis()->SetTimeDisplay(1);
  timeHist1->Draw();

  c->cd(2);
  timeHist1a->GetXaxis()->SetTimeDisplay(1);
  timeHist1a->GetXaxis()->SetTimeFormat("#splitline{%Hh%M}{%d/%m%y}%F1-1-1970 00:00:00 GMT");
  timeHist1a->Draw();

  c->cd(3);
  timeHist1b->GetXaxis()->SetTimeDisplay(1);
  timeHist1b->GetXaxis()->SetTimeFormat("#splitline{%Hh%M}{%y}%F1-1-1970 00:00:00");
  timeHist1b->Draw();

  c->cd(4);
  timeHist1c->GetXaxis()->SetTimeDisplay(1);
  timeHist1c->GetXaxis()->SetTimeFormat("#splitline{%Hh%M}{%y}%FXXXX");
  timeHist1c->Draw();



  c = new TCanvas("t2","t2");
  timeHist2->GetXaxis()->SetTimeDisplay(1);
  timeHist2->Draw();

}