Set default value for DateTime in optional parameter [duplicate]

Answer 1

Don't use an optional parameter:

public SomeClassInit(Guid docId, DateTime addedOn)
{
    SomeClassInitCore(docId, addedOn);
}

public SomeClassInit(Guid docId)
{
    SomeClassInitCore(docId, null);
}

private SomeClassInitCore(Guid docId, DateTime? addedOn)
{
    // set default value
    if (addedOn.IsNull) addedOn = DateTime.Now;

    //Init codes here
}