Panchang is our own Indian calendar, which follows traditional units of Hindu timekeeping and shows important dates for each month. They also show sun-rise/sun-set times as well as details of eclipses & Choghadiya (auspicious times). Occasionally there may be confusion about exact tithi/day as different people follow different guidance. In such cases, you can consult your own nearby temple/shastriji or you can refer to Sanatan Panchang website (http://sanatanpanchang.com)