Fixed points · The assumed-fixed · Element
The dependencies
What has grown up around the date.
The part
What it is
Other work scheduled around it, external expectations, customer habits. These are the real cost of moving it.
Sometimes substantial and sometimes nothing at all, and the difference is only visible on inspection.
The smallest level
The attributes it carries
Each attribute is one of the framework’s shared types. What a date is, and how it is written, is defined once for the whole model — the note here says what it means in this particular place.
The other elements in the assumed-fixed
The candidates
Which dates have no external authority behind them.
LearnThe test
What happens if it moves.
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