Only then will our historical practice be truly common.
A final argument: the AD/BC system is factually wrong.
In a sixth-century treatise on the calculation of Easter, Dionysius 'the Little' first proposed to count from the birth of Christ to avoid honouring the hated persecutor Diocletian.
His idea was popularised in England by the Venerable Bede, who added the notion of counting backwards for dates 'Before Christ'.
If we can have pagan weeks, months and seconds, why not Christian years?