at best you can get copies of w-2s for a fee from the Social Security adm but they will be for a specific year and not indicate the the dates you started or left.
TurboTax has no work history for you. Even the income you entered is only by the years in which you received the income; it is never broken down by which months you worked for a particular employer. W-2's and 1099's do not have months on them--just years. Social Security can provide a work history, but I am not sure if it is broken down by more than the years either.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**