Relativity Calendar vs Trajectory
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.
Trajectory
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Detects the trajectories of shapes moving along a parabolic path
Screenshots
Verdict
The clearest difference is ads: Relativity Calendar at none against Trajectory's shown. Relativity Calendar also leads on device support (3 vs 1) and iOS requirement (15.0 vs 17.7.2). Trajectory's advantage is update cadence (fortnightly vs every 2 months). On price 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Relativity Calendar ships an update every 2 months, Trajectory fortnightly. The most recent releases landed on September 28, 2026 and October 11, 2026 respectively.
| Parameter | Relativity Calendar | Trajectory |
|---|---|---|
| Price | Free | Free |
| Rating | 4.9 (17 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 17 — better | — |
| Update frequency | Every 2 months | Fortnightly — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPod, Apple Watch — better | iPhone |
| Requires iOS | 15.0 — better | 17.7.2 |
| Further details — not scored | ||
| Size | 3 MB | 36 MB |
| Age rating | 4+ | 4+ |
| Developer | Jonathan Cole | Hideaki Uchikoshi |
In-app purchases
Relativity Calendar
No in-app purchases
Trajectory
No in-app purchases
Questions
Is Relativity Calendar free?
Is Trajectory free?
Do Relativity Calendar or Trajectory have ads?
Which is updated more often, Relativity Calendar or Trajectory?
Other comparisons
