Ideally I would like to have a good way to configure this, via some sort of "strftime++" syntax or something which allows different format strings depending on

Ideally I would like to have a good way to configure this, via some sort of "strftime++" syntax or something which allows different format strings depending on the age of the file. For me, personally, this has been working quite well. If something is older than two days I don't often care about the exact time it was changed. While "yst" and "dby" are indeed slightly cryptic, it's quite mnemonic and reads naturally: "yesterday 15:14", "day before yesterday 07:42". Something like "-1 15:15" and "-2 07:42"? Rather less so.