var res = from d in data.Table
             group d by d.date.Date into gd
             select new
             {
                    Date = gd.Key,
                    Value = gd.Min()
             };

var mnt = from d in data
	 group d by new { d.Date.Month, d.Date.Year } into gd
	 select new
	 {
		 Month = gd.Key.Month,
		 Year = gd.Key.Year,
		 Value = gd.Min()
	 };

group d.Value by