Server-Side Calculation Engine
All calculations on yrCalc are processed server-side on our backend using PHP's native, high-precision DateTimeImmutable and DateInterval engine. We do not rely on rough approximations (such as assuming every month has 30 days or every year has 365 days).
calendar_month Calendar Arithmetic
Our algorithms strictly observe the Gregorian calendar, properly handling 28, 29, 30, and 31-day months and leap years (checkdate).
timer Interval Breakdown
Differences are decomposed into exact integer days, full completed weeks (days / 7), completed months, and full year-month-day tuples.