How can I specify the latest time of day with DateTime

Question

I am using a System.DateTime object to allow a user to select a date range. The user is only able to select a date (not time) using a third party calendar so I

Answer 1

Your question has already been answered, but IMHO a better way is not to bother attempting to subtract a tick, a second, or whatever from the end of the range, and compare using strictly less than.

So that if you want all dates in an inclusive range from startDate to endDate, ignoring the time, you could use the following in C#:

if ((myDate >= startDate.Date) && (myDate < endDate.Date.AddDays(1)))
{
    // ... it's in the range
}

or in T-SQL, assuming your @StartDate and @EndDate are exactly midnight, something like:

WHERE SomeDate >= @StartDate AND SomeDate < DATEADD(d,1,@EndDate)

UPDATE

Updated example to show an inclusive range in response to comments.