Date Difference: Calendar Days vs Business Logic
2026-05-14
Computing spans between dates for contracts, rentals, and HR—watch inclusive vs exclusive ranges.
Clarify whether day one counts: leases and notices often use inclusive start or end rules by jurisdiction.
Calendar days include weekends; business-day calculators exclude them—pick the tool that matches your policy.
Crossing February in leap years adds a day to some month-difference breakdowns.
Store dates in UTC for systems; explain local calendar results to humans.