The 'Donor Giving Analysis' dashboard (and others) does provide option to input specific date range to configure results. We often compare more than current and previous fiscal year results. Adding the 'between these dates' feature would allow results to be generated for more timeframes.
We also have this problem - I would love to be able to rely on dashboards for accurate information, but because we can't be more specific in the dates, dashboards are useless in some ways.
What it also needs are options for "last 30 days" or "last 7 days" or "last X days". Our gifs are entered the day after they are received (mail comes late afternoon). So on the 1st we are still entering gifts from the 31st. But the dashboard has already changed to this month so the recent gifts list is now blank and the gifts being entered never show on that dashboard.