figure 1 (timeline of the Anno Domini era)

* year 1 ₁ year 2 ₂ year 3 ₃ …… _{time (in years)}

in which year x = the year x = the year x after Christ

figure 2 (timeline of the complete Christian era)

…… _-3 year -3 _-2 year -2 _-1 year -1 ₀ year 1 ₁ year 2 ₂ year 3 ₃ …… _{time
(in years)}

in which year -x = the year -x = the year x before Christ

…… _-3 year -2 _-2 year -1 _-1 year 0 ₀ year 1 ₁ year 2 ₂ year 3 ₃ …… _{time (in years)}

in which year 0 not exactly coincides with the year -1 (of the Christian era)