bar reports differ from other options in this category - they require quite extensive configuration.
leaving the screen will lose all information, thus making their usage quite cumbersome.
i predict users will cry out for report saving, so i am filing this in advance

named settings/profiles should be savable per report category (currently added items semi-travel between them).

to be truly usable, this would need one more thing, though - relative periods.
this seems to be tricky both from ui and functionality viewpoint, so i can open a separate issue in case report saving is implemented first.

this basically means that instead of a fixed period user can also choose "last full n [working/holi] days", "last full x [working] hours", "last full y weeks/months/years"...
then, when run, report would figure out what is the period it needs. period list should be customisable,
thinking about this, all of these options would also require "z units back" - as in "report about last full week, but 2 weeks ago".