We use Redshift for reporting (or, more accurately, the tool we use for reporting uses Redshift).

It’s pretty simple to calculate daily rollups, using datetrunc:

select date_trunc('day', foo) date, sum(bar) bar
from [baz]
where ...
group by date

Or just by casting to a date:

select [foo:date] date, sum(bar) bar
from [baz]
where ...
group by date

But what if you want to slice into smaller time periods?

The easiest way I’ve found, is to use to_char, and format the timestamp appropriately. e.g.

select to_char(foo, 'YYYY-MM-DD HH24:MI') date, sum(bar) bar
from [baz]
where ...
group by date