Fidamen

Convert Weeks to Days – Time Converter

This converter converts a numeric value in weeks to the equivalent number of days using the standard fixed relationship between these units. It is intended for scheduling, planning, data normalization, and quick unit-check calculations.

The mathematical conversion is exact in the sense that one week equals seven days. Use the guidance below when converting fractional weeks, when mapping durations onto calendar dates, or when work-week/business-week conventions matter.

Updated Nov 15, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record eeb0d981c2da • Reviewed by Fidamen Standards Committee

Interactive Converter

Convert between week and day with precision rounding.

Quick reference table

WeekDay
1 wkDAY 7.00 d
5 wkDAY 35.00 d
10 wkDAY 70.00 d
25 wkDAY 175.00 d
50 wkDAY 350.00 d
100 wkDAY 700.00 d

Methodology

The conversion uses the fixed, definition-level relationship that one week equals seven days. For pure duration arithmetic (for example, converting a duration measured in weeks into a duration measured in days), multiply the numeric week value by 7.

For calendar calculations that map a week count onto specific dates, consider calendar rules such as ISO week numbering (ISO 8601) and local week-start conventions; those rules affect date alignment but do not change the weeks-to-days multiplication.

Where traceability, measurement uncertainty, or timestamp synchronization matter, follow time and measurement guidance from authoritative bodies. See NIST for time and frequency references, ISO 8601 for week/date formats, IEEE standards for precise timing and synchronization, and applicable occupational rules for work-week definitions.

Worked examples

2 weeks → 14 days

0.5 weeks → 3.5 days

52 weeks → 364 days

F.A.Q.

Is one week always seven days?

Yes. In standard civil and scientific unit definitions used for duration arithmetic, one week is defined as seven days. Week numbering systems and work-week definitions do not alter this fixed multiplicative relationship.

How should I handle fractional weeks?

Multiply the fractional week value by 7. For user-facing output, round to the number of decimal places appropriate for your context (for example, hours or days).

Does daylight saving time or leap seconds affect this conversion?

No for unit conversion: one week equals seven days as a unit relationship. However, when converting between calendar dates or clock times (for example, adding a week to a timestamp), daylight saving time shifts and leap seconds affect clock times and may require time-zone-aware date arithmetic.

What is the difference between a calendar week and a business week?

A calendar week is any seven-day period and is commonly aligned with ISO or local definitions of week start. A business week typically refers to working days within that week (commonly Monday–Friday) and is a counting convention that excludes weekends; converting between weeks and business days requires applying the business-day rule, not just multiplying by seven.

How precise is this conversion?

The mathematical conversion is exact. Practical precision depends on input precision and how you choose to round the output. For high-precision timing or regulatory compliance, follow guidance from standards bodies cited below and document rounding rules.

Sources & citations

Further resources

Versioning & Change Control

Audit record (versions, QA runs, reviewer sign-off, and evidence).

Record ID: eeb0d981c2da

What changed (latest)

v1.0.0 • 2025-11-15 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Public QA status

PASS — golden 25 + edge 120

Last run: 2026-01-23 • Run: golden-edge-2026-01-23

Engine

v1.0.0

Data

Baseline (no external datasets)

Content

v1.0.0

UI

v1.0.0

Governance

Last updated: Nov 15, 2025

Reviewed by: Fidamen Standards Committee (Review board)

Credentials: Internal QA

Risk level: low

Reviewer profile (entity)

Fidamen Standards Committee

Review board

Internal QA

Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person

Semantic versioning

  • MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
  • MINOR: New features or fields that do not change existing outputs for the same inputs.
  • PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.

Review protocol

  • Verify formulas and unit definitions against primary standards or datasets.
  • Run golden-case regression suite and edge-case suite.
  • Record reviewer sign-off with credentials and scope.
  • Document assumptions, limitations, and jurisdiction applicability.

Assumptions & limitations

  • Uses exact unit definitions from the Fidamen conversion library.
  • Internal calculations use double precision; display rounding follows the unit's configured decimal places.
  • Not a substitute for calibrated instruments in regulated contexts.
  • Jurisdiction-specific rules may require official guidance.

Change log

v1.0.0 • 2025-11-15 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: 3c2c935d8626