I agree.
But I suppose you don't disagree that the dates are standard based on the definition I provided (i.e. what the majority of academics believed based on scientific and historical evidence).
In 1939 the Second World War started. This is a fact. This a historical true. Correct?
The French Revolution started in 1789. This is a fact. This is a historical true. Correct?
Julius Caesar was killed in 44 BC by Brutus. This is a fact. This is a historical true. Correct?
In 221 BC China was unified by Shih Huang Ti. This is a fact. This is a historical true. Correct?

For this reason I repeat my main question (to everyone). What they teach you in Russian schools.
1. When Slavs came to settle in the Balkan (Period of Time)?
2. When Ukrainians (if the exist as a different nation) came to live in the are where is today Ukraine?
Also I add an other more general question:
1. Is there any map showing the historical movement of Slavs tribes. From where they started? When they started? How they expand to the different countries?

My question is historical. I don't want a debate with anyone.

I am not asking for opinion I am asking of what they are teaching you in Russian and other schools. For me is very important.
In my schools they don't teach us anything about Slavs.