Membership | How TimePeriod work

TimePeriod describe a formal timeframe of membership validation For example a membership record on 10th of February 2023 should be valid throught 1st of January 2023 to 31th of December 2023 if the formal timeframe chosen by association is the solar year for members registered in 2023

@ZompaSenior has proposed to implement it with a start and a duration (using RelativeDeltaField field)

Implementation

class TimePeriod:
    start = models.DateField(...)
    duration = models.DateField(...) 
    price = models.MoneyField(...)

Question: using end_date instead of duration

An additional end=models.DateField(...) field could be added with a validation which impose that one and only one between duration or end field should be set. Or substituting duration with end. This should permit more fine selection of date interval, but make more complex to set regular interval (yearly, bimonthly, etc, etc)...I think response is obvious

Some notes

TimePeriod.duration == None could be used to intend a membership which doesn't end
TimePeriod.start == None could be used to intend a membership which is retroactively always valid
is not completely clear what field price is referring to, as is I think is the default price to create a membership for that period. In fact discounted or free memberships should be permits. I think this last observation is linked to logic inside Transaction connected to membership model

What to do

[x] Convert default in duration from formal string to a relativedelta from a function
[x] Specify price help text
[x] (optional) Add some method to create common relativedelta timeframe)

ConoscereLinux / asso-django