Notes: All timings are represented in 12-hour notation in local time of Fairfield, United States with DST adjustment (if applicable).
Hours which are past midnight are suffixed with next day date. In Panchang day starts and ends with sunrise.
As per Nirnaya-Sindhu,
अथ नवरात्रपारणानिर्णयः। सा च दशम्यां कार्या॥
the Navratri Parana is done when Navami Tithi is over and Dashami Tithi prevails. As the book mentions, Navratri fasting has been suggested from Pratipada to Navami and to follow this guideline Magha Gupta Navratri fasting should be observed throughout Navami Tithi.
Drik Panchang Magha Gupta Navratri Parana time to break fasting is based on the rules mentioned in Nirnaya-Sindhu.