As far as I understand it, you are referring with your question to the duration for an independent individual residence permit after divorce according to 31 para. 1 AufenthG. It is my understanding that the relevant period of three years is in principle calculated from the date of marriage. This means that in order to obtain such an individual residence permit, you must - as a minimum requirement - have been married for more than three years and have lived together in Germany for more than three years.
Please note that apparently only the time during which you and your wife have legally resided in Germany is taken into account for the calculation of this time. This is generally only the case with a residence title or a fiction of residence.
However, the above statements are based on online research. For more detailed information, I advise you to consult a lawyer who specialises in such matters.
Nevertheless, I hope you consider this answer helpful.