weekday-skip-days

To calculate weekdays skipping intercalary days, you must subtract skipped day indexes from the total elapsed days to find the regular days elapsed, then add the anchor weekday index and compute the result modulo seven.

Weekday computation returns incorrect dates because raw day index calculations fail when skipped non-weekday days are present. You must classify regular and skipped days, then derive the weekday from the adjusted regular-day count.

Computing a weekday while skipping intercalary days requires the anchor weekday index of a known reference date, the total elapsed days, and the set of skipped day indexes to determine the correct regular days elapsed.

Leap years introduce additional intercalary days into the date computation cycle. The calculation must validate these edge cases by correctly identifying and subtracting all leap-year skipped day indexes before deriving the weekday modulo seven.

Yes, weekday calculation with skipped days works for negative year scenarios. The logic validates edge cases including negative years by consistently applying the skipped day subtraction to the total elapsed days before modulo arithmetic.