So I opened up Zabkar’s seminal work, Hymns to Isis of Her Temple at Philae (1988), and lo and behold, there are festivals listed in the hymn and comment sections of Hymn VI. Most notably, the Sixth-Day Feast (Swnt) and the Seventh-Day Feast (Dnit) are mentioned in Zabkar’s commentary. The Sixth Day Feast is mentioned in Hymn VI itself. From pages 80-85, Zabkar mentions that the Sixth Day Feast was a time when: the Udjat Eye was Completed, the Akhu were honored, when Wesir (Osiris) was honored possibly as a moon deity, when Ra was honored and the Sun’s journey to the Underworld was a part of the mythos for this festival. The Seventh-Day Festival had more to do with Ra as a sun deity.
Aset per the hymn was given a “Great Oblation” during this festival in Heliopolis. Not much is known about Her worship from Heliopolis so this is interesting. According to Zabkar, She may have been given these festivals because of the prominence of Heliopolis and Ra as the sun god.
Anyway, if you decide to honor Aset as a deity on these two festivals, you could honor Aset, as the Lady of the West, Wesir and the Akhu on the Sixth Day Feast and honor Aset as a Solar Eye of Ra on the Seventh Day Feast.
Just for calendar notes, these are the Sixth and Seventh days of every month.