{
float x[]={1204210366,1204210396};
float y[]={1.,2.};

new TCanvas("offset 1/1/1970 00h00","offset 1/1/1970 00h00");

TGraph mgr(2,x,y);
mgr.SetMarkerStyle(20);

mgr.Draw("ap");
mgr.GetXaxis()->SetTimeDisplay(1);
mgr.GetXaxis()->SetTimeFormat("%H:%M %F 1970-01-01 00:00:00");

new TCanvas("offset 1/1/1970 01h00","offset 1/1/1970 01h00");

TGraph mgr2(2,x,y);
mgr2.SetMarkerStyle(20);

mgr2.Draw("ap");
mgr2.GetXaxis()->SetTimeDisplay(1);
mgr2.GetXaxis()->SetTimeFormat("%H:%M %F 1970-01-01 01:00:00");

new TCanvas("offset 1/1/1970 02h00","offset 1/1/1970 02h00");

TGraph mgr3(2,x,y);
mgr3.SetMarkerStyle(20);

mgr3.Draw("ap");
mgr3.GetXaxis()->SetTimeDisplay(1);
mgr3.GetXaxis()->SetTimeFormat("%H:%M %F 1970-01-01 02:00:00");

}