____________________________
| Id  |   Dato   | fechaHora |
|_____|__________|___________|
| AI  | Varchar  | DateTime  |
|_____|__________|___________|

SELECT CONVERT(DateTime,GETDATE(),101) as 'Dia', COUNT(*) as 'cantidad'
  FROM table
  Group by DAY([fechaHora]), MONTH([fechaHora])
  ''Grup by [fechaHora]
  ''Group by Convert(DateTime,GETDATE(),101), COUNT(*) as 'cantidad'

SELECT TO_Date(fechaHora,'dd-mm'), count(*)
FROM Table
Group by TO_DATE(fechahora,'dd-mm').