# About year count and notation

As we believe that we have identified a major error regarding the synchronisation of our  Christian calendar with the Roman calendar, we need to make clear in every single case which year we are referring to in order to avoid confusion.

The time line as such is of course continuous and there are no errors (gaps or phantom years) in the time that has passed. But our allocation of events on the time line can be erroneous, i.e. events can be misdated. Therefore we abandon the use of the common AD/BC notation on this web site, except in direct citations.

To solve our problem, we could have used the scientific notation BP (before present, i.e. before 1950), e.g. BP 1150 which would mean AD 800. But in doing so we always would have to "translate" to the AD/BC notation anyway, because it provides the dates we recognize as it is widely used by historians.

Instead we use a notation that is similar to that used by the NASA Eclipse Web Site, that means the AD years are counted from 1 up to present time, and the BC years are counted from -1 down through the past. There is also a year -0 in order to facilitate arithmetic calculations. In certain cases we set the prefix Astr to explicate that we mean the year number in a continuous array (i.e. the astronomical time line), and not a nominal date.

We regard events which are dated from the Roman time horizon as too old by more than 200 years. These events will retain their nominal dates but with an identifying prefix, e.g. RomAD 79 (AD 79) or RomBC 150 (150 BC).
Example 1: The eruption of the Vesuvius which killed Pliny the Elder took place in the year of the ninth consulship of Vespasian, and the seventh consulship of Titus,  which is commonly interpreted as RomAD 79. According to our own interpretation, this year would be Astr 311 instead, i.e. 232 years later.
Example 2: Gaius Julius Caesar was murdered in RomBC 44, which according to our interpretation is Astr 189. Also in this case the dates are 232 years apart (though 44 + 189 = 233), because of the change from BC to AD time where the year 0 does not exist.
Example 3: The so far youngest astronomically datable cuneiform clay tablet found in Babylon contains observations from AD 74/75. As this is a dating on the continuous time line, we would refer to the year as Astr 74/75.

Please note that things are even more complicated. When dealing with dendrochronological dates within the Roman time complex, the corrective factor is 218 years instead of 232. This is because the Roman dendro complex, according to our interpretation, appears to be not properly synchronized with Roman history.