I know that different peoples have had different ways to count the years. Some cultures, like our own, begin a count-up from a particular event (birth of Jesus in the West, Hijra in Islam), and others, such as Rome, would say something like "It is the thirtieth year of the current Consul". I've been very interested in the Iroquois Leage lately, so I was wondering how they counted the years.
In the speeches of that era, I haven't seen anyone mention the current year with such specificity, and various memorable events (notable treaties, wars, etc.) were usually used to reference the recent past. So in daily life, people wouldn't be referring to years based on a formalized long-term calendar.
For deeper history, however, there is a traditional method for referencing periods of time. This was done by numbering the Adodaroh / Tadodaho, the presiding official of the Grand Council, since the foundation of the League. So historical events since the founding of the League, such as splintering away of the Erie, would be referred to as occurring during the time of 9th Adodaroh and the like. Unfortunately, that's as specific as the oral record gets. We know how many Adodaroh's there have been (146 since Sidney Hill became Adodaroh in 2002), but we don't know how long each served in this capacity or whether there were any lengthy gaps between the death of one Adodaroh and the appointment of the next (as there was with the six-year gap between Adodaroh Hill and his predecessor). Currently, attempts to sync the traditional Iroquoian historical paradigm up with the Western one have been a mess. The best we've got is using it, the archaeological record, and astronomical calculations to give us a likely starting point in 1142 for the First Adodaroh.