The holidays listed are based off of the large and small Hathor from The Temple Calendars of Ancient Egypt by Sherif el-Sabban, in addition to other sources which cite the holidays observed in Dendera.
Holidays
Akhet
1 Akhet 20-25 Tekh
4 Akhet 12-30 Ka-her-Ka
Peret
Shomu
3 Shomu, New Moon The Festival of the Beautiful Union