<!--
{
  "availability" : [
    "iOS: 2.0.0 -",
    "iPadOS: 2.0.0 -",
    "macCatalyst: 13.0.0 -",
    "macOS: 10.0.0 -",
    "tvOS: 9.0.0 -",
    "visionOS: 1.0.0 -",
    "watchOS: 2.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "Foundation",
  "identifier" : "/documentation/Foundation/NSTimeZone/isDaylightSavingTime(for:)",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
      "Foundation"
    ],
    "preciseIdentifier" : "c:objc(cs)NSTimeZone(im)isDaylightSavingTimeForDate:"
  },
  "title" : "isDaylightSavingTime(for:)"
}
-->

# isDaylightSavingTime(for:)

Indicates whether the receiver uses daylight saving time on a given date.

```
func isDaylightSavingTime(for aDate: Date) -> Bool
```

## Parameters

`aDate`

The date against which to test the receiver.

## Return Value

<doc://com.apple.documentation/documentation/Swift/true> if the receiver uses daylight saving time at `aDate`, otherwise <doc://com.apple.documentation/documentation/Swift/false>.

---

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)