Relativity Calendar vs Datum
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Relativity Calendar
This app redefines how you view dates by allowing you to express any day relative to any month. See custom dates like 'May 32nd' or 'March 93rd' at a glance. It offers home screen widgets and Apple Watch complications for easy access.
- Express dates relative to any month
- Home screen widgets with color customization
- Apple Watch complications
- iOS 16 Lock Screen widgets
- Track custom dates and holidays
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Relativity Calendar is an app that tells you what day it is, relative to any month. For example, June 1st can also be written as May 32nd or March 93rd. Set any month you want, and you'll be able to see it at a glance in your widgets and Apple Watch! Whether it's the month of your birth, an important holiday, or Truck Month, Relativity Calendar will (more or less) help you keep track. Features: - Pick any month, even if it doesn't make sense. Especially if it doesn't make sense. - Full support for home screen widgets, with full color customization - Full support for Apple Watch, including complications - Supports iOS 16 Lock Screen widgets.
Datum
A minimalist calendar application designed for Apple devices, offering a clean interface and customizable widgets for iOS, macOS, and watchOS. View upcoming events, daily schedules, and monthly overviews directly from your home screen or watch face.
- Minimalist calendar interface
- Lockscreen widgets for iOS
- Event display widgets
- Calendar widgets with event marks
- watchOS calendar and complications
- Support for iPhone, iPad, Mac, and Apple Watch
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Datum is a minimalistic iOS, watchOS, macOS and visionOS calendar app. For iOS there are Lockscreen Widgets that show you the current date and there are Lockscreen Widgets that show up to 3 events for today. The iOS and macOS apps include the following widgets: - a small widget that shows the current date and at the bottom the events for this day - a small widget that shows a calendar with up to 3 event marks for each day - a medium widget that shows the same as the first small widget and on the right side a calendar with up to 3 event marks for each day - a large widget that shows the same as the medium widget and a list of the upcoming events - a extra large widget that shows a calendar and a list of the upcoming events (only for iPadOS 15+) The watchOS app shows a calendar with up to 3 event marks for each day. You can switch to the next/previous month by tapping on the arrows at the bottom of the calendar. You can view all events for each day by tapping on a day. There are also complications for all watchfaces included that show you the current date.
Screenshots
Verdict
The clearest difference is price: Relativity Calendar at Free against Datum's $1.99. Relativity Calendar also leads on update cadence (every 2 months vs every 3 months) and iOS requirement (15.0 vs 17.6). Datum's advantage is device support (5 vs 3). On review sentiment, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Relativity Calendar is free to download; Datum costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Relativity Calendar ships an update every 2 months, Datum every 3 months. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.
| Parameter | Relativity Calendar | Datum |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 4.9 (17 ratings) — better | — |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 17 — better | — |
| Update frequency | Every 2 months — better | Every 3 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Devices | iPhone, iPod, Apple Watch | iPhone, iPad, Mac, Apple Watch, Vision Pro — better |
| Requires iOS | 15.0 — better | 17.6 |
| Further details — not scored | ||
| Size | 3 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | Jonathan Cole | Michael Lindinger |
Customer experience
Relativity Calendar
Datum
In-app purchases
Relativity Calendar
No in-app purchases
Datum
No in-app purchases
Questions
Is Relativity Calendar free?
Is Datum free?
Do Relativity Calendar or Datum have ads?
Which is updated more often, Relativity Calendar or Datum?
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