TCanvas *ct2 = new TCanvas("ct2","ct2",10,10,700,500);

TDatime T0(2003, 1, 1, 0, 0, 0);
int X0 = T0.Convert();
gStyle->SetTimeOffset(X0);

TDatime T1(2002, 9, 23, 0, 0, 0);
int X1 = T1.Convert()-X0;

TDatime T2(2003, 3, 7, 0, 0, 0);
int X2 = T2.Convert(1)-X0;

TH1F * h1 = new TH1F("h1","test",100,X1,X2);

TRandom r;
for (Int_t i=0;i<30000;i++) {
   Double_t noise = r.Gaus(0.5*(X1+X2),0.1*(X2-X1));
   h1->Fill(noise);
}

h1->GetXaxis()->SetTimeDisplay(1);
h1->GetXaxis()->SetLabelSize(0.03);
h1->GetXaxis()->SetTimeFormat("%Y/%m/%d");
h1->Draw();
return ct2;

gROOT->GetListOfCanvases()->Draw()