구체적으로 뭐가 어렵나요?? 

이런걸 원하시는 건지 모르겠는데요!!!

select count(seq) from table

where SUBSTRING(visitdt, 1, 4) = '년도'

and SUBSTRING(visitdt, 5, 2) = '월'

and SUBSTRING(visitdt, 7,2) = '일'

and SUBSTRING(visitdt, 9, 2) = '시간'

and SUBSTRING(visitdt, 11, 2) = '분'

and SUBSTRING(visitdt, 13, 2) = '초'

visitdt 의 자료형이 datetime이었다면

//====================================================// DATEPART (MSSQL)
 SELECT
 GETDATE(),
 DATEPART(year, GETDATE()) AS '년도',
 DATEPART(quarter, GETDATE()) AS '분기(1-4)',
 DATEPART(month, GETDATE()) AS '달',
 DATEPART(dayofyear, GETDATE()) AS '일수(1-366)',
 DATEPART(day, GETDATE()) AS '일자',
 DATEPART(week, GETDATE()) AS '주수(1-53)',
 DATEPART(weekday, GETDATE()) AS '요일',
 DATEPART(hour, GETDATE()) AS '시간',
 DATEPART(minute, GETDATE()) AS '분',
 DATEPART(second, GETDATE()) AS '초',
 DATEPART(millisecond, GETDATE()) AS '밀리초'
 
 //---------------------------------------------------// 결과
 GETDATE : 2005-08-05 17:54:14.013 
 년도 : 2005
 분기 : 3
 달 : 8
 일수 : 217
 일자 : 5
 주소(1-53): 32
 요일 : 6
 시간 : 17
 분 : 54
 초 : 14
 밀리초 : 13
 //====================================================// DATEPART (MSSQL)

 //====================================================// DATENAME (MSSQL)
 SELECT
 GETDATE(),
 DATENAME(year, GETDATE()) AS '년도',
 DATENAME(quarter, GETDATE()) AS '분기(1-4)',
 DATENAME(month, GETDATE()) AS '달',
 DATENAME(dayofyear, GETDATE()) AS '일수(1-366)',
 CASE LEN(DATENAME(day, GETDATE()))
  WHEN 1 THEN '0' + DATENAME(day, GETDATE())
  ELSE DATENAME(day, GETDATE())
 END AS '일자',
 DATENAME(week, GETDATE()) AS '주수(1-53)',
 DATENAME(weekday, GETDATE()) AS '요일',
 
 CASE LEN(DATENAME(hour, GETDATE()))
  WHEN 1 THEN '0' + DATENAME(hour, GETDATE())
  ELSE DATENAME(hour, GETDATE())
 END AS '시간',
 CASE LEN(DATENAME(minute, GETDATE()))
  WHEN 1 THEN '0' + DATENAME(minute, GETDATE())
  ELSE DATENAME(minute, GETDATE())
 END AS '분',
 CASE LEN(DATENAME(second, GETDATE()))
  WHEN 1 THEN '0' + DATENAME(second, GETDATE())
  ELSE DATENAME(second, GETDATE())
 END AS '초',
 DATENAME(millisecond, GETDATE()) AS '밀리초'
 
 //---------------------------------------------------// 결과
 GETDATE : 2005-08-05 17:54:14.013
 년도 : 2005
 분기 : 3
 달 : 08
 일수 : 217
 일자 : 05
 주소(1-53): 32
 요일 : 금요일
 시간 : 17
 분 : 54
 초 : 14
 밀리초 : 13
 //====================================================// DATENAME (MSSQL)

이럲게 사용할 수 있습니다.