2001-01-01 00:00:00.000 inserted into database instead 2000-12-31 23:59:59

Question

I have a method which adds row to database (sql server 2005). Something is wrong with its because , when I have a row with UpdateDate 2000-12-31 23:59:59 it inserts 2001-01-01 00:00:00.000. Is it possible? Culture of environment is polish if it is important. It's a magic for me :/

private void AddInvestmentStatus(InvestmentData.StatusyInwestycjiRow investmentStatusesRow)
{
    SqlCommand cmd = new SqlCommand("AddInvestmentStatus");
    cmd.CommandType = CommandType.StoredProcedure;


    SqlParameter param1 = new SqlParameter("@InvestmentId", SqlDbType.BigInt);
    param1.Value = investmentStatusesRow.InvestmentId;
    cmd.Parameters.Add(param1);
    cmd.Parameters.AddWithValue("@enumInvestmentStatusID", investmentStatusesRow.EnumInvestmentStatusID);
    cmd.Parameters.AddWithValue("@modifiedBy", "System");
    cmd.Parameters.AddWithValue("@UpdateDate", investmentStatusesRow.UpdateDate);
    cmd.Parameters.AddWithValue("@ModifiedOn", investmentStatusesRow.ModifiedOn);
    cmd.Parameters.AddWithValue("@dataVersion", investmentStatusesRow.DataVersion);


    cmd.Connection = new SqlConnection(MyProgram.Properties.Settings.Default.ConnectionString);
    if (cmd.Connection.State != ConnectionState.Open)
        cmd.Connection.Open();

    try
    {
        cmd.ExecuteNonQuery();
    }
    catch (Exception e)
    {
        throw;
    }
}

}

create PROCEDURE [dbo].[AddInvestmentStatus] 
    @inwestmentID bigint,
    @enumInvestmentStatusId bigint,
    @updateDate datetime,
    @dataVersion int,
    @modifiedBy nvarchar(50),
    @modifiedOn datetime
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    DECLARE @investmentStatusesID bigint

    INSERT INTO StatusyInwestycji(InwestycjaID)
    VALUES (@inwestmentID)

    SELECT @investmentStatusesID = SCOPE_IDENTITY();

    INSERT INTO StatusyInwestycjiData(InvestmentStatusId, EnumStatusInwestycjiID,
            UpdateDate, DataVersion, ModifiedBy, ModifiedOn)
    VALUES (@investmentStatusesID, @enumInvestmentStatusId,
            @updateDate, @dataVersion, @modifiedBy, @modifiedOn)

END

EDIT:

my date:

{2000-12-31 22:59:59}
    Date: {2000-12-31 00:00:00}
    Day: 31
    DayOfWeek: Sunday
    DayOfYear: 366
    Hour: 22
    Kind: Utc
    Millisecond: 999
    Minute: 59
    Month: 12
    Second: 59
    Ticks: 631139003999990000
    TimeOfDay: {22:59:59.9990000}
    Year: 2000

Answer 1

Are you sure you're entering 23:59:59.000000 or are you entering 23:59:59.9999999?

SQL DateTime datatype has precision of 3.33ms (it will round to 0ms, 3ms, 7ms increments), meaning your 23:59:59.9999 will be rounded to 00:00:00.000000 of the next day.