Working calendars (skipping weekends + holidays)

By default, projects use a standard 5-day work week — Saturday and Sunday are off. CPM, leveling, and the drag-cascade all measure durations in *working* days, so a Mon–Fri task is 5 days even though calendar-wise it's 4 (end-minus-start).

Today: weekends are off by default. v5 will add a per-project holidays editor + per-resource availability overrides.

What the calendar affects:
• **CPM** — earliest/latest start + finish dates skip off-days
• **Cascade** — when you drag a task, dependents land on the next working day, not Saturday
• **Leveling** — capacity is daily, but only working days count toward over-allocation
• **Monte Carlo** — sampled durations are working days

What it doesn't affect (yet):
• The visible bar in the Timeline still spans the entire calendar window — this is intentional, so the visual aligns with the date axis. v5 will add an option to hide weekend columns.

Tip: if you have a non-standard schedule (e.g. 4-day week, 6-day construction), reach out — the data model already supports custom off-days; we just haven't exposed the editor yet.