Calendar Mathematics: The Gregorian System & Date Duration Calculations
Measuring time between two dates involves accounting for irregular astronomical solar cycles. The modern Gregorian calendar, introduced in 1582 by Pope Gregory XIII to replace the Julian calendar, corrected the solar drift by defining precise leap year rules (a year is a leap year if divisible by 4, except end-of-century years which must be divisible by 400).
1. Business Days (Workdays) Calculation Logic
Standard business day algorithms iterate through every calendar day within the [start, end] interval, applying modulo arithmetic against day-of-week indexes:
Frequently Asked Questions (FAQ)
How does the business days calculation work?
The business days calculation counts only standard workdays (Monday through Friday) between the start and end dates, automatically excluding Saturdays and Sundays.
How is exact age calculated across months with varying days?
The age calculation tracks exact calendar month boundaries (accounting for 28, 29, 30, and 31-day months as well as leap years) to provide your precise age in years, months, days, and total hours lived.
Can I add business days to a target deadline date?
Yes. Select the 'Add / Subtract Days' mode and check 'Exclude weekends' to calculate the exact future business delivery date.