Topic collection

Time & Numbers

Ten independent, practical guides about time & numbers. Explore concepts, check your assumptions, and discover what to read next.

Understand offsets, locations, and changing clock rules.

Avoid off-by-one errors in calendars and deadlines.

Learn the 4, 100, and 400-year rule.

Calculate increases, declines, and base effects.

Report rate changes without exaggeration.

Choose sensible precision for reports and estimates.

Make basic measurements comparable.

Scale recipes, mixtures, and quantities carefully.

Choose the right summary for skewed data.

Spot implausible numerical results before acting.

Dedicated subject portals may be developed in the future. No external subdomain is linked until it is actually live.