Supported Features
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VoiceOver
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Voice Control
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Larger Text
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Dark Interface
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Differentiate Without Colour Alone
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Sufficient Contrast
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Reduced Motion
WhichWeek
Know your ISO week instantly
Free · Designed for iPad. Not verified for macOS.
Always know which week it is. WhichWeek shows your ISO week number with a single glance — and counts days between any two dates.
WhichWeek is the fastest way to know your ISO week number.
Open the app and your current ISO week number is front and center — bold, clear, and impossible to miss. No digging through a calendar. No mental arithmetic. Just the week number.
WEEK VIEW
• Your current ISO week number, large and legible
• The exact date range for that week (Monday to Sunday)
• Step forward or back through weeks and years with the stepper controls
• Tap Today to jump straight back to the current week
• Leap year indicator so you never lose track of the extra day
DAYS VIEW
• Pick any two dates and instantly see the number of days between them
• Broken down into full weeks and remaining days
• Perfect for project planning, countdowns, and date arithmetic
DESIGNED WITH CARE
• Pure SwiftUI — fast, native, and responsive
• Supports Dynamic Type for accessibility
• Full Dark Mode and Light Mode support
• Works in portrait and landscape
• Available on iPhone, iPad, Mac, and Apple Watch
ISO WEEK NUMBERS
ISO 8601 defines week numbering used widely in business, finance, logistics, and project management across Europe and beyond. Week 1 is the week containing the first Thursday of the year. WhichWeek follows this standard precisely.
NO ADS. NO TRACKING. NO SUBSCRIPTIONS.
WhichWeek is a one-time purchase. No accounts required, no data collected, no network requests made.
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
The developer, Arthur Kahwa, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
The developer indicated that this app supports the following accessibility features. Learn More
Information
- Size
- 3.1 MB
- Category
- Productivity
- Compatibility
Requires iOS 26.4 or later.
- iPhone
Requires iOS 26.4 or later. - iPad
Requires iPadOS 26.4 or later. - Mac
Requires macOS 26.4 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.4 or later.
- iPhone
- Languages
English and 9 more
- English, Arabic, French, German, Italian, Japanese, Korean, Portuguese, Simplified Chinese, Spanish
- Age Rating
4+
- 4+
- Provider
Arthur Nsereko Kahwa
- Arthur Nsereko Kahwa has identified itself as a trader for this app and confirmed that this product or service complies with European Union law.
- Address
Riedlstr. 7A
82140 Olching
Germany - Phone Number
+49 1787985344 - Email
arthur_kahwa@chapter.de
- Copyright
- © 2026 Chapter