What turn number is 2020AD?

[Souron]

Simple question.

Given the default turn interval, what turn does the game end on when it ends at 2020AD?

 

[Prof. Garfield]

It depends on the difficulty level and (at lower levels) the map size. At deity, it is always 420 turns regardless of map size.

 

[Souron]

Thank you.

 

[Lefty Scaevola]

Here is a table
http://www.civfanatics.com/civ2/strategy/scrolls/#Turns
under the title of time warp explaining the different amount of years per turn for the different difficulty levels of civ 2. It was made by player test and thus may not be complete or accurate for all situations.
Exploring the 'Main Site' articles can reveal all sorts of tidbits.