The jj git backend happens to update only one of the two timestamps. There's not a lot of talk about the author date on the jj issue tracker.
I did not dig into the history of the code, so I can't say if it was an explicit design decision or just how it was implemented. Since there hasn't been a lot of demand to change anything here, I didn't see any active discussion about the choice.
I did not dig into the history of the code, so I can't say if it was an explicit design decision or just how it was implemented. Since there hasn't been a lot of demand to change anything here, I didn't see any active discussion about the choice.
EDIT: oh I see martin has said 'we just followed git' here: https://news.ycombinator.com/item?id=45599741