Abu Hurairah and 'Aishah (May Allah be pleased with them) said:
The Prophet (ﷺ) prohibited observing continuous voluntary fasts beyond one day.[Al-Bukhari and Muslim]. (RU)
App reference (RU): Book 18, Hadith 254 (RU)
Arabic/English book reference (RU): Book 18, Hadith 1764 (RU)