The third lunar day of the bright fortnight of Vaishaka month (Vaishakha Shukla Paksha Tritiya), is celebrated as Akshaya Tritiya.
This answer, citing Wikipedia, claims that Vishnu took the form of Hayagriva (the horse-headed deity) on the Akshaya Tritiya.
Further, this magazine, besides numerous other sources claim that Vishnu manifested as the famous Nara-Narayana rishis on the tithi of Akshaya-Tritiya.
Does anywhere in the canonical text it is stated that Vishnu manifested as Hayagriva, and Nara-Narayana rishi, on the tithi of Akshaya-Tritiya?