# Aerzeit vs Drying Day

The clearest difference is ads: Aerzeit at none against Drying Day's shown. Aerzeit also leads on update cadence (every 3 days vs every 3 weeks). On price, in-app purchases, device support and iOS requirement there is nothing between them.

Both are free to download. Aerzeit sells 1 in-app purchase, starting at $9.99 per year and Drying Day sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Aerzeit ships an update every 3 days, Drying Day every 3 weeks. The most recent releases landed on November 5, 2026 and November 10, 2026 respectively.

## The numbers

| Metric | Aerzeit | Drying Day |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/aerzeit-when-to-open-windows/id6787749300/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 3 days** | Every 3 weeks |
| Monetization | Freemium | — |
| Size | 28 MB | 27 MB |
| Requires iOS | 16.4 | **15.0** |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Samuel Harrold](https://appshunter.io/developer/6775297361) | [I OSTAPENKO & Y OSTAPENKO](https://appshunter.io/developer/6799116433) |

## What reviewers say

### Aerzeit

[App page](https://appshunter.io/ios/app/aerzeit-when-to-open-windows/id6787749300)

This app analyzes outdoor conditions for the next 48 hours to identify optimal times for ventilation. It allows customization of temperature ranges and environmental factors like rain, humidity, and pollen to help you decide when to open windows.

**Highlights:** 48-hour outdoor condition forecast, Customizable temperature ranges, Rain, humidity, wind, air quality, pollen filters, UV and sun position tracking, Apple Watch app and complication, Home Screen widget, Multi-language support

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Aerzeit Premium | $9.99 | per year |


### Drying Day

[App page](https://appshunter.io/ios/app/drying-day/id6802211157)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Small thank-you | $0.49 | one-time |
| Thank-you | $1.99 | one-time |
| Big thank-you | $2.99 | one-time |


## Frequently asked questions

### Is Aerzeit free?

Aerzeit is free to download, with in-app purchases available.

### Is Drying Day free?

Drying Day is free to download, with in-app purchases available.

### Do Aerzeit or Drying Day have ads?

Drying Day shows ads; Aerzeit does not.

### Which is updated more often, Aerzeit or Drying Day?

Aerzeit ships an update every 3 days, and Drying Day every 3 weeks. Most recently, Aerzeit was updated on November 5, 2026 and Drying Day on November 10, 2026.

---

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