Как решить Преобразование не удалось при преобразовании значения nvarchar?

CREATE TABLE #Temp (VisitingCount int, [Time] int, [Date] nvarchar(50) )
DECLARE @DateNow DATETIME,@i int,@Time int, @Date nvarchar(50)
set @DateNow='00:00'  
set @i=1;  
while(@i^60;48)  
    begin  
        set @DateNow = DATEADD(minute, 30, @DateNow)
        set @Time = (datepart(hour,@DateNow)*60+datepart(minute,@DateNow))/30 
        set @Date = CONVERT(VARCHAR(5),@DateNow, 108)
        insert into #Temp(VisitingCount,[Time],[Date]) values(0,@Time,@Date )
        set @i=@i+1
    end

select Sum(VisitingCount)as VisitingCount, [Time],Date
from (
  select Sum(VisitingCount)as VisitingCount, [Time],Date
    from #Temp group by [Time],Date
  Union All
    select count(page) as VisitingCount,CONVERT(VARCHAR(5),Date, 108), 
    (datepart(hour,Date)*60+datepart(minute,Date))/30 as [Time]
    from scr_SecuristLog
    where Date between '2009-05-12' and '2009-05-13'
    GROUP BY (datepart(hour,Date)*60+datepart(minute,Date))/30,CONVERT(VARCHAR(5),Date, 108)
  ) X
group by [Time],Date
order by 2 asc  

Error

Сообщение 245, уровень 16, состояние 1, строка 1 Преобразование завершилось неудачно при преобразовании значения nvarchar '00:30' в тип данных int.

ERROR AREA: select Sum(VisitingCount)as VisitingCount, [Time],Date.................