I have the following code -
DateTime timeStamp;
timeStamp = System.Convert.ToDateTime(y.InnerText);
Where y.InnerText is
How can I set the format of the DateTime object?
You can't. DateTime values don't have formats, any more than int or double values do. When you want to convert them to/from strings, that's where you specify any formatting information.
Instead, you should use parameterized SQL and avoid converting the DateTime value back into a string in the first place. This is a general best practice - don't include values in your SQL string; parameterized SQL has multiple benefits:
I would also suggest that instead of using Convert.ToDateTime, you specify your expected format when parsing. For example:
timeStamp = DateTime.ParseExact(y.InnerText,
"dd/MM/yyyy HH:mm:ss",
CultureInfo.InvariantCulture);
Basically, the two rules I try to apply are: