I was unable to find any corresponding dates from pre-Christian history for these two days. So I will talk a bit about my family’s information, which has an established calendar complete with intercalendary days.
In the reckoning handed down to me, both Yules – Cron and Sol, ‘Dark/Night’ and ‘Sun’ – are twelve day long celebrations. What was not given me was what todo on each of those twelve days. No matter, I still use this method to calculate the year for myself. For example, where the two Yules are twelve days, the two Equinox’s – Graineiri and Graintuiri, ‘Gráinne’s Rise and Set’ – are six days, and the Between Tides are three and nine days.
Granted, there is no singular calendar for all people for all times, and many ancient peoples recognized any number of seasonal tides, from three to four, to six to eight, so it’s generally assumed that the current configuration is modern. And I for one am glad of that because it helps calculate the lunar calendar.