[Dirvish] Changing expiration dates of existing backups?

[Michael Richardson]

> is there a semi-automatic way to change the expiration dates of existing
> backups next to editing their summaries manually?
>
> Sorry if its well-known, I searched for it but I didn't find anything.

Well, it's only one step removed, but using sed inline (`sed -i
's/oldregexp/newregexp/`) with carefully tested regular expressions works
well to update expiration dates on a large number of backups quickly when
time is short.

Cheers,
Michael