System.Data.SqlClient.MetaType.FromDateTime C# (CSharp) Method

        public static TdsDateTime FromDateTime(DateTime dateTime, byte cb)
        {
            SqlDateTime sqlDateTime;
            TdsDateTime tdsDateTime = new TdsDateTime();

            Debug.Assert(cb == 8 || cb == 4, "Invalid date time size!");

            if (cb == 8)
            {
                sqlDateTime = new SqlDateTime(dateTime);
                tdsDateTime.time = sqlDateTime.TimeTicks;
            }
            else
            {
                // note that smalldatetime is days & minutes.
                // Adding 30 seconds ensures proper roundup if the seconds are >= 30
                // The AddSeconds function handles eventual carryover
                sqlDateTime = new SqlDateTime(dateTime.AddSeconds(30));
                tdsDateTime.time = sqlDateTime.TimeTicks / SqlDateTime.SQLTicksPerMinute;
            }
            tdsDateTime.days = sqlDateTime.DayTicks;
            return tdsDateTime;
        }

        // valid for DateTime, SmallDateTime, Date, DateTime2
        internal void SetDateTime(DateTime value)
        {
            Debug.Assert(
                SmiXetterAccessMap.IsSetterAccessValid(_metaData, SmiXetterTypeCode.XetDateTime));
            if (SqlDbType.Variant == _metaData.SqlDbType)
            {
                if ((_variantType != null) && (_variantType.SqlDbType == SqlDbType.DateTime2))
                {
                    _stateObj.Parser.WriteSqlVariantDateTime2(value, _stateObj);
                }
                else if ((_variantType != null) && (_variantType.SqlDbType == SqlDbType.Date))
                {
                    _stateObj.Parser.WriteSqlVariantDate(value, _stateObj);
                }
                else
                {
                    TdsDateTime dt = MetaType.FromDateTime(value, 8);
                    _stateObj.Parser.WriteSqlVariantHeader(10, TdsEnums.SQLDATETIME, 0, _stateObj);
                    _stateObj.Parser.WriteInt(dt.days, _stateObj);
                    _stateObj.Parser.WriteInt(dt.time, _stateObj);
                }

                // Clean the variant metadata to prevent sharing it with next row.
                // As a reminder, SetVariantType raises an assert if _variantType is not clean
                _variantType = null;
            }
            else
            {
                _stateObj.WriteByte((byte)_metaData.MaxLength);
                if (SqlDbType.SmallDateTime == _metaData.SqlDbType)
                {
                    TdsDateTime dt = MetaType.FromDateTime(value, (byte)_metaData.MaxLength);
                    Debug.Assert(0 <= dt.days && dt.days <= ushort.MaxValue, "Invalid DateTime '" + value + "' for SmallDateTime");

                    _stateObj.Parser.WriteShort(dt.days, _stateObj);
                    _stateObj.Parser.WriteShort(dt.time, _stateObj);
                }
                else if (SqlDbType.DateTime == _metaData.SqlDbType)
                {
                    TdsDateTime dt = MetaType.FromDateTime(value, (byte)_metaData.MaxLength);
                    _stateObj.Parser.WriteInt(dt.days, _stateObj);
                    _stateObj.Parser.WriteInt(dt.time, _stateObj);
                }
                else
                { // date and datetime2
                    int days = value.Subtract(DateTime.MinValue).Days;
                    if (SqlDbType.DateTime2 == _metaData.SqlDbType)
                    {
                        long time = value.TimeOfDay.Ticks / TdsEnums.TICKS_FROM_SCALE[_metaData.Scale];
                        _stateObj.WriteByteArray(BitConverter.GetBytes(time), (int)_metaData.MaxLength - 3, 0);
                    }
                    _stateObj.WriteByteArray(BitConverter.GetBytes(days), 3, 0);
                }
            }
        }