Nearest weekday to a date

Use it free in the browser for scheduling, payroll cutoffs, and SLA alignment, or call the API at $0.002 per successful request when you need reproducible weekday snaps in CI, reporting pipelines, or product features.

What nearest weekday means and what the response contains

Finding the nearest Monday-to-Friday weekday answers a different question from next named weekday, previous weekday, or multi-day business-day offsets: it asks which single civil day is closest to the input while staying inside the Monday through Friday set, treating Saturday and Sunday as non-weekdays that must be reassigned. Distance is measured in whole calendar midnights on the proleptic Gregorian timeline interpreted as a UTC date string with no time-of-day and no local timezone conversion. For any Monday through Friday the offset is zero and result equals the normalized input. If you need a named target weekday on or after a base, holiday-aware business days, or weekend counts between two stamps, use those dedicated tools; this page answers only the nearest Mon–Fri snap for one explicit ISO date. For Saturday the previous Friday is one day away and the following Monday is two days away, so the nearest weekday is Friday with offset_days equal to negative one. For Sunday the following Monday is one day away and the previous Friday is two days away, so the nearest weekday is Monday with offset_days equal to positive one. The calculator returns the normalized base date, the result ISO string, offset_days, boolean flags is_weekend and shifted, the base weekday name and ISO weekday number Monday equals one through Sunday equals seven, the same pair for the result, result year month and day fields, base components for easy piping, and a short formula reminder. Rejected cases include a missing date field, wrong shapes such as 2024/03/16, impossible months, and days that do not exist such as 2023-02-29.

How the date is read and how the result stays reproducible

The string must match four digits, a hyphen, two digits, another hyphen, and two digits; leading or trailing spaces are trimmed, but partial dates, ordinal day-of-year alone, month names, and timestamps with a time component are not expanded here. After parsing, the year must fall between 1 and 9999, the month between 1 and 12, and the day between 1 and the true length of that month in that year, with leap years following the Gregorian rule of divisible by four except century years not divisible by four hundred. The preferred field is date, but aliases iso_date, d, value, base, and from are accepted so spreadsheets, query strings, and typed forms can reuse the same contract without renaming columns. Internally the engine obtains the base day of week with Sakamoto pure-integer arithmetic on a Sunday-zero scale, maps Saturday to a minus-one offset and Sunday to a plus-one offset while leaving Monday through Friday at zero, converts the civil triple to a proleptic Gregorian serial day count using the well-known days_from_civil mapping, adds the integer offset, then recovers year, month, and day with civil_from_days. Pair the free browser run on this page with the priced API when you need the identical nearest weekday inside an automated pipeline that must not drift under host locale settings or daylight-saving transitions.

Where nearest-weekday arithmetic fits in operations, payroll, and software

On this page the work runs entirely in your browser; through the API each successful lookup costs $0.002, failed validation is not charged, and nothing is stored after the response returns. That split — free interactive exploration and a priced, identical API — matches the rest of the KIT tier-A catalog and lets you move from a one-off check to a pipeline without changing the mathematical result.