<!--
{
  "availability" : [
    "iOS: 11.2.0 - 18.0.0",
    "iPadOS: 11.2.0 - 18.0.0",
    "macCatalyst: 13.1.0 - 18.0.0",
    "macOS: 10.13.2 - 15.0.0",
    "tvOS: 11.2.0 - 18.0.0",
    "visionOS: 1.0.0 - 2.0.0",
    "watchOS: 6.2.0 - 11.0.0"
  ],
  "documentType" : "symbol",
  "framework" : "StoreKit",
  "identifier" : "/documentation/StoreKit/SKProductSubscriptionPeriod/unit",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Property",
  "symbol" : {
    "kind" : "Instance Property",
    "modules" : [
      "StoreKit"
    ],
    "preciseIdentifier" : "c:objc(cs)SKProductSubscriptionPeriod(py)unit"
  },
  "title" : "unit"
}
-->

# unit

The increment of time that a subscription period is specified in.

```
var unit: SKProduct.PeriodUnit { get }
```

## Discussion

The units used to specify a subscription period include day, week, month, and year, as defined in [`SKProduct.PeriodUnit`](/documentation/StoreKit/SKProduct/PeriodUnit).

To calculate the duration of one subscription period, multiply the [`unit`](/documentation/StoreKit/SKProductSubscriptionPeriod/unit) by the number of units ([`numberOfUnits`](/documentation/StoreKit/SKProductSubscriptionPeriod/numberOfUnits)).

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)