earth takes 365 days 6 hours and 56 minutes ,Right? to make a leap year?

 no, earth takes 365 days and 6 hrs every year to revolve once around the sun.in 4 yaers, 6hrs *4 = 24 hrs, which makes one day thus 365 days + 1 day = 366 days. so leap year occurs every 4 years and that one day is added to february.