# Taiwan Datum vs Selene

The clearest difference is price: Selene at Free against Taiwan Datum's $1.99. Selene also leads on update cadence (every 3 days vs every 2 months) and review sentiment (91% vs 73%). Taiwan Datum's advantage is iOS requirement (13.0 vs 16.0). On ads, in-app purchases and device support there is nothing between them.

Selene is free to download; Taiwan Datum costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Taiwan Datum ships an update every 2 months, Selene every 3 days. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Taiwan Datum | Selene |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | — | **[4.7 (31 ratings)](https://appshunter.io/ios/app/selene-shift-calendar/id1410053842/reviews)** |
| Number of ratings | — | **31** |
| Positive reviews | 72.7% of reviews | **90.9% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 days** |
| Monetization | Paid | **Free** |
| Size | 3 MB | 65 MB |
| Requires iOS | **13.0** | 16.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [HUNG HSUN LIN](https://appshunter.io/developer/482586427) | [Jiawen Sun](https://appshunter.io/developer/1809677007) |

## What reviewers say

### Taiwan Datum

[App page](https://appshunter.io/ios/app/taiwan-datum/id620301625)

This app measures coordinates in Taiwan using WGS84, TWD97, and TWD67 systems. It allows users to export data as CSV and attach photos, videos, and voice recordings to measurements.

**Highlights:** WGS84, TWD97, TWD67 coordinate systems, CSV data export, Attach photos, Attach videos, Attach voice records, Download media via iTunes

**Features:** Vision Pro support

**In-app purchases:** none


### Selene

[App page](https://appshunter.io/ios/app/selene-shift-calendar/id1410053842)

Manage rotating and irregular work schedules with custom alarms, widgets, and sharing options. Export schedules as PDFs, images, or CSVs, and sync across devices. Offers 30 themes and dark mode support.

**Highlights:** Rotating shift scheduling, Custom shift alarms, Home screen widgets, Schedule comparison, Shift statistics, Export to PDF, CSV, and system calendar, iCloud sync

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

**In-app purchases:** none


## Frequently asked questions

### Is Taiwan Datum free?

Taiwan Datum costs $1.99, with no in-app purchases.

### Is Selene free?

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

### Do Taiwan Datum or Selene have ads?

Neither Taiwan Datum nor Selene shows ads.

### Which is updated more often, Taiwan Datum or Selene?

Taiwan Datum ships an update every 2 months, and Selene every 3 days. Most recently, Taiwan Datum was updated on November 1, 2026 and Selene on November 3, 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.*