query on time axis

Dear Rooters,

I have problem with time axis. I am plotting some monitor data. Each data points are collected in every 10 minutes. And I want to plot from 00:03(hour:minute) of a day to 23:53(hh:mm) of that day. and I am calculating time as

inttime=time_int1*3600+time_int2*60+Sln*600;  where

          time_int1 = hour
          time_int2 = minute

time_int1 & time_int1 get value from data file.

Sln*600 = number of second -> gap between two data sample.

then I am doing following in graph option

    gr1->GetXaxis()->SetTimeDisplay(1);
    gr1->GetXaxis()->SetTimeFormat("%I:%M %p");

But the axis gives me 5:30 AM to onwards even if time value in data files are started from 00:03 (24h).
But I can't understand how to set offset Is this a problem ?
Kindly suggest me what to do.

Thanks
Satya

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Satya
Research Student,
High Energy Physics, India.