Actually in VB6, DateDiff function considered date but in VB.Net considered with time.
for Example:
CurDate = "06/27/2011 4:01:15 AM"
FindDate = "06/26/2011 7:01:15 PM" '==> with subtraction of "-540" minutes
in VB,
n = DateDiff("d", FindDate, CurDate)
'==> it's returned "1" value because i mentioned interval as "d". so it's consider only date.
in VB.Net,
Dim dateDiff AS TimeSpan = FindDate.Subtract(CurDate)
n = dateDiff.Days
'==> it's returned "0" value because it's consider with time. so it's not reached 24 hours.
Solution:
i changed VB.Net Code,
n = DateDiff(DateInterval.Day, FindDate.Date, CurDate.Date)
So now it's consider only date.
Now i am getting "1" value