Use `CFRunLoopTimerCreateWithHandler` to create timer

Package.swift

@@ -5,10 +5,10 @@ import PackageDescription
 let package = Package(
     name: "Schedule",
     platforms: [
-        .macOS(.v10_12),
-        .iOS(.v10),
-        .tvOS(.v10),
-        .watchOS(.v3)
+        .macOS(.v10_11),
+        .iOS(.v9),
+        .tvOS(.v9),
+        .watchOS(.v2)
     ],
     products: [
         .library(name: "Schedule", targets: ["Schedule"])

Schedule.xcodeproj/Schedule_Info.plist

@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
   <key>CFBundleDevelopmentRegion</key>
@@ -15,7 +14,7 @@
   <key>CFBundlePackageType</key>
   <string>FMWK</string>
   <key>CFBundleShortVersionString</key>
-	<string>2.0.2</string>
+  <string>1.0</string>
   <key>CFBundleSignature</key>
   <string>????</string>
   <key>CFBundleVersion</key>

Schedule.xcodeproj/xcshareddata/xcschemes/Schedule-Package.xcscheme

@@ -26,12 +26,10 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      codeCoverageEnabled = "YES"
       shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
          <TestableReference
-            skipped = "NO"
-            parallelizable = "YES">
+            skipped = "NO">
             <BuildableReference
                BuildableIdentifier = "primary"
                BlueprintIdentifier = "Schedule::ScheduleTests"
@@ -41,8 +39,6 @@
             </BuildableReference>
          </TestableReference>
       </Testables>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </TestAction>
    <LaunchAction
       buildConfiguration = "Debug"
@@ -54,17 +50,6 @@
       debugDocumentVersioning = "YES"
       debugServiceExtension = "internal"
       allowLocationSimulation = "YES">
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "Schedule::Schedule"
-            BuildableName = "Schedule.framework"
-            BlueprintName = "Schedule"
-            ReferencedContainer = "container:Schedule.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </LaunchAction>
    <ProfileAction
       buildConfiguration = "Release"

Sources/Schedule/RunLoopTask.swift

@@ -59,14 +59,10 @@ private final class RunLoopTask: Task {
             timer.fireDate = Date()
         }
         
-        timer = Timer(
-            fire: Date.distantFuture,
-            interval: .greatestFiniteMagnitude,
-            repeats: true
-        ) { [weak self] _ in
+        timer = CFRunLoopTimerCreateWithHandler(kCFAllocatorDefault, Date.distantFuture.timeIntervalSinceReferenceDate, .greatestFiniteMagnitude, 0, 0, { [weak self] _ in
             guard let self = self else { return }
             action(self)
-        }
+        })
 
         RunLoop.current.add(timer, forMode: mode)
     }