Will this help...

DECLARE @Hourly INT

SELECT @Hourly = 1

SELECT Col1,Col2 FROM TableA

WHERE

(CASE WHEN @Hourly = 1 THEN TableA.LoadDateTime

ELSE CONVERT(VARCHAR(8),TableA.LoadDateTime,112)

END) >=

(CASE WHEN @Hourly = 1 THEN @TodaysDate

ELSE CONVERT(VARCHAR(8),@TodaysDate,112)

END)