@Retained earnings is a term usually employed by accountants only for shareholder corporations. It is a corporation’s cumulative earnings since formations minus all dividends declared. So it represents the net of all profits (income less expenses) that have not been distributed to stockholders. Thus, for a particular fiscal year, the retained earnings formula is:
Beginning retained earnings + Net income during the period - Dividends paid = Ending retained earnings
Retained earnings regardless of the type of company organization. For a sole trader/proprietor, it is a form of what is usually termed owner’s equity. For partnerships with capital accounts, it is the unallocated profits. Of course, financially, these options are equivalent.
In your situation, you should start with the retained earnings balance from your last complete fiscal year, then add and subtract relevant amounts for 2016-2017 until October 2, 2016.
If your quoted statement is true, why can’t you recreate the 2016-2017 fiscal year records? If, in fact, you cannot, you still need to transfer
Retained earnings amounts to appropriate income and expense accounts by journal entry. Otherwise, your P&L for 2016-2017 will be wrong, leading to difficulties in year-end reporting and tax filing.