Custom time granularity for alerts

[#1]

Currently time granularity can be set to hourly, daily, weekly, monthly.

Idea:

Please allow custom time granularities: e.g. last hour, last 6 hours, last 12 hours, last 48 hours, etc.

[#2]

I think this would be a good feature! Sometimes you do not need the full days data, but want it rolling on an hourly basis.