I'm looking for ideas/information about managing temporal data with Active Record (Rails). One example would be the emplyoment history (working 100% in january, but only 80% from february up to now). This proably would be easy to tackle with a traditional 'has-many :eployment_parts'. But there's another case where the user can plan something like a todo list, which the user can change over time (this todo is valid from Jan-March, another one is valid from Jan-April, and then with changed details from May to August).
I know, there's no silver bullet solution for these kind of requirements, but I'd like to collect here some ideas/docmentations/plugins about this topic. It looks like there hasn't been done much in this area for rails, at least nothing which got public.
Please, if you have an idea, link or thought, drop a short answer!
Links so far: