# Date.Time Calculator vs Relativity Calendar

The clearest difference is review sentiment: Relativity Calendar at 100% against Date.Time Calculator's 0%. Relativity Calendar also leads on price (Free vs $0.99) and update cadence (every 2 months vs every 5 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Relativity Calendar is free to download; Date.Time Calculator costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Date.Time Calculator ships an update every 5 months, Relativity Calendar every 2 months. The most recent releases landed on November 1, 2026 and November 7, 2026 respectively.

## The numbers

| Metric | Date.Time Calculator | Relativity Calendar |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | — | **[4.9 (17 ratings)](https://appshunter.io/ios/app/relativity-calendar/id1481494405/reviews)** |
| Number of ratings | — | **17** |
| Positive reviews | 0.0% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | Paid | **Free** |
| Size | 1 MB | 3 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPod | **iPhone, iPod, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Noriaki HASHIBA](https://appshunter.io/developer/978336077) | [Jonathan Cole](https://appshunter.io/developer/1093735229) |

## What reviewers say

### Date.Time Calculator

[App page](https://appshunter.io/ios/app/datetime-calculator/id978336078)

Calculate date and time differences, intervals, and perform unit conversions with a pure calculator interface. Useful for determining future or past dates, calculating total time for multiple events, and converting between various time units and POSIX time.

**Highlights:** Date and time point calculations, Time interval calculations, Unit conversion of time, POSIX time interconversion, Time zone mutual conversion, Arithmetic operations with time

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Relativity Calendar

[App page](https://appshunter.io/ios/app/relativity-calendar/id1481494405)

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.

**Highlights:** 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

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Date.Time Calculator free?

Date.Time Calculator costs $0.99, with no in-app purchases.

### Is Relativity Calendar free?

Relativity Calendar is free to download, with no in-app purchases.

### Do Date.Time Calculator or Relativity Calendar have ads?

Neither Date.Time Calculator nor Relativity Calendar shows ads.

### Which is updated more often, Date.Time Calculator or Relativity Calendar?

Date.Time Calculator ships an update every 5 months, and Relativity Calendar every 2 months. Most recently, Date.Time Calculator was updated on November 1, 2026 and Relativity Calendar on November 7, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*