Calculadora de Diferença de Datas

Overview

Calculating the difference between two dates seems trivial — but anyone who has tried to write the code knows the edge cases pile up quickly. Leap years, varying month lengths, time zones, daylight saving transitions, calendar reforms (Russia switched calendars in 1918), and ambiguous month arithmetic (Jan 31 + 1 month = Feb 28? Mar 3?) all complicate the answer. This calculator handles all standard cases for the Gregorian calendar (1582 onward), giving you a breakdown in years, months, weeks, days, hours, minutes, and seconds.

How It Works

The tool computes the raw difference using JavaScript's Date object (millisecond precision), then breaks it into hierarchical units. Years are counted as completed years (Feb 1 → Jan 31 next year = 0 years, not 1). Months use day-of-month preservation when possible. The calculator also offers business-days-only mode for project planning (excludes weekends; doesn't account for holidays unless you provide them).

When to Use This

Calculate days until a deadline, weeks until a vacation, months between life events (anniversaries, work milestones), or precise age between birth and a target date. Project managers use it for estimating timelines. Anyone tracking habits (X days streak) needs precise day counts across timezone-crossing trips. Legal contracts often specify dates 30/60/90 days from signing.

Frequently Asked Questions