I'm designing a project that will be developed in Django and I had a design philosophy question. In my app I need to track information like current week. This is related to the current week in the NFL (1-17) and can be calculated based on other models in the system (schedule and the current day for example). Since this information gets updated once a week, and will be used quite often in the app, does it make sense to store this information in a model (db table) of its own and just run the update weekly?
There is other information that might be useful to store as well (date/time of first and last games of the current week) so would a model of something like "current weeks information" be appropriate for this, even though the data can be calculated on the fly?
would a model of something like "current weeks information" be appropriate for this, even though the data can be calculated on the fly?
It might be. You can calculate the date Easter falls on, but few applications do that. The calculation is far from dead simple, and any error would have to be treated as a bug fix. But if you store Easter dates in a table, any error can be fixed by anyone who can update calendar data.
It's simple to calculate USA holidays like Martin Luther King Day (observed on the 3rd Monday in January), President's Day (observed on the 3rd Monday in February), and Labor Day (observed on the 1st Monday in September). It's also pretty easy to calculate factory production weeks, which parallels your problem in some ways.
But when I'm building tables for businesses to use for scheduling, estimating, process control, and so on, I like to have the dates that are important to the business--holidays, for example--stored in a table rather than in procedural (calculating) code. The main advantage is that they can be collected, reviewed, and approved or corrected by relatively unskilled employees instead of needing a programmer.
So, if I were in your shoes, I would probably store the weeks in a table. A secondary advantage (or maybe the main advantage, in your case) is that most queries involving weeks might take advantage of indexes on the start and end dates.