I build enterprise systems that preserve the decisions behind a calendar, a client workspace and an archive, rather than allow an empty field or convenient default to decide for the business.
The resource calendar looked like an improvement over scattered planning sheets. It gave managers one view of the people and hours they wanted to allocate. In 2018 I supported a rule that multiplied forty colleagues by thirty scheduled hours and presented 1,200 hours as available for campaign work. Daniel Qavzori asked where approved leave and training appeared. The system had made the total easier to see while making a crucial subtraction disappear.
A system should carry the decision the business has made and reveal the decision still missing. A default becomes dangerous when its convenience makes that distinction hard to see.