diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5da5404..dffa37b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,15 @@
 # DevFoundation Changelog
 
 
+## 1.4.0: October 8, 2025
+
+  - We’ve added `Duration`-based alternatives to all APIs that take a `TimeInterval`. Specifically,
+
+      - We’ve added an overload of `DateProvider.offset(by:)` that takes a `Duration`.
+      - We’ve added an overload of `ExpiringValue.init(_:lifetimeDuration:)` that takes a
+        `Duration`.
+
+
 ## 1.3.0: October 8, 2025
 
   - We’ve added a computed property spelled `timeInterval` to `Duration`, which returns the
diff --git a/Sources/DevFoundation/Date Providers/OffsetDateProvider.swift b/Sources/DevFoundation/Date Providers/OffsetDateProvider.swift
index 9188f58..a21dde1 100644
--- a/Sources/DevFoundation/Date Providers/OffsetDateProvider.swift	
+++ b/Sources/DevFoundation/Date Providers/OffsetDateProvider.swift	
@@ -13,38 +13,46 @@ struct OffsetDateProvider<Base>: DateProvider where Base: DateProvider {
     private let base: Base
 
     /// The time interval that this provider adds to the base provider’s dates.
-    private let offset: TimeInterval
+    private let offset: Duration
 
 
     /// Creates a new `OffsetDateProvider` with the specified base and offset.
     ///
     /// - Parameters:
     ///   - base: The base date provider whose dates this provider’s dates are relative to.
-    ///   - offset: The time interval that the new date provider adds to its base provider’s dates.
-    init(base: Base, offset: TimeInterval) {
+    ///   - offset: The duration that the new date provider adds to its base provider’s dates.
+    init(base: Base, offset: Duration) {
         self.base = base
         self.offset = offset
     }
 
 
     var now: Date {
-        return base.now + offset
+        return base.now + offset.timeInterval
     }
 }
 
 
 extension OffsetDateProvider: CustomStringConvertible {
     public var description: String {
-        return "\(base).offset(by: \(offset))"
+        return "\(base).offset(by: \(offset.timeInterval))"
     }
 }
 
 
 extension DateProvider {
+    /// Returns a relative date provider whose current date is offset from this one’s by a constant duration.
+    ///
+    /// - Parameter offset: The duration to add to this date provider’s dates.
+    public func offset(by offset: Duration) -> some DateProvider {
+        return OffsetDateProvider(base: self, offset: offset)
+    }
+
+
     /// Returns a relative date provider whose current date is offset from this one’s by a constant time interval.
     ///
     /// - Parameter offset: The time interval to add to this date provider’s dates.
     public func offset(by offset: TimeInterval) -> some DateProvider {
-        return OffsetDateProvider(base: self, offset: offset)
+        return self.offset(by: .seconds(offset))
     }
 }
diff --git a/Sources/DevFoundation/Utility Types/ExpiringValue.swift b/Sources/DevFoundation/Utility Types/ExpiringValue.swift
index 1bf065d..7cd520c 100644
--- a/Sources/DevFoundation/Utility Types/ExpiringValue.swift	
+++ b/Sources/DevFoundation/Utility Types/ExpiringValue.swift	
@@ -34,6 +34,18 @@ public struct ExpiringValue<Value> {
     }
 
 
+    /// Creates a new expiring value with the specified value and lifetime duration.
+    ///
+    /// - Parameters:
+    ///   - value: The value.
+    ///   - lifetimeDuration: The length of the value’s lifetime.
+    public init(_ value: Value, lifetimeDuration: Duration) {
+        let now = DateProviders.current.now
+        self.value = value
+        self.lifetimeRange = now ... (now + lifetimeDuration.timeInterval)
+    }
+
+
     /// Creates a new expiring value with the specified value and lifetime duration.
     ///
     /// The value’s lifetime starts now and ends `lifetimeDuration` seconds in the future.
@@ -42,9 +54,7 @@ public struct ExpiringValue<Value> {
     ///   - value: The value.
     ///   - lifetimeDuration: The length of the value’s lifetime.
     public init(_ value: Value, lifetimeDuration: TimeInterval) {
-        let now = DateProviders.current.now
-        self.value = value
-        self.lifetimeRange = now ... (now + lifetimeDuration)
+        self.init(value, lifetimeDuration: .seconds(lifetimeDuration))
     }