Hi Stéphane 
Thanks for your request! I understand the need, and indeed, there’s a real gap between « 1 day » and « 7 days » in the current durations.
However, I don’t want to go with a fully configurable list of durations in the settings. The philosophy of Gladys is to be simple and ready to use: I prefer good default choices that suit the majority, rather than settings screens that 95% of users will never open, but that everyone will have to « pay » for in complexity (management interface, dynamic translations, migrations, tricky cases like a deleted duration still used by a chart…). It’s configuration for the sake of configuration: your real problem isn’t the lack of a generic system, it’s a missing duration in the scale 
So, I suggest instead adding « Last 3 days » natively to the proposed durations, for everyone.