@@ -91,31 +91,26 @@ extension NSTimer {
 
 // MARK: - Time extensions
 
-private let milliDivider: Double    = 1000
-private let secondsInMinute: Double = 60
-private let minutesInHour: Double   = 60
-private let hoursInDay: Double      = 24
-
 extension Double {
 
-    private func assertOneOrLess(value: Double) -> Double {
-        assert(self <= 1, "🤓 Use plural property for numbers above 1.")
+    private func assertOne(value: Double) -> Double {
+        assert(self == 1, "🤓 Use plural property for numbers other than 1")
         return value
     }
 
-    public var millisecond: NSTimeInterval  { return assertOneOrLess(milliseconds) }
-    public var milliseconds: NSTimeInterval { return self / milliDivider }
-    public var ms: NSTimeInterval           { return milliseconds }
+    public var millisecond: NSTimeInterval  { return assertOne(milliseconds) }
+    public var milliseconds: NSTimeInterval { return self / 1000 }
+    public var ms: NSTimeInterval           { return self / 1000 }
 
-    public var second: NSTimeInterval       { return assertOneOrLess(seconds) }
+    public var second: NSTimeInterval       { return assertOne(seconds) }
     public var seconds: NSTimeInterval      { return self }
 
-    public var minute: NSTimeInterval       { return assertOneOrLess(minutes) }
-    public var minutes: NSTimeInterval      { return self * secondsInMinute }
+    public var minute: NSTimeInterval       { return assertOne(minutes) }
+    public var minutes: NSTimeInterval      { return self * 60 }
 
-    public var hour: NSTimeInterval         { return assertOneOrLess(hours)}
-    public var hours: NSTimeInterval        { return minutes * minutesInHour }
+    public var hour: NSTimeInterval         { return assertOne(hours) }
+    public var hours: NSTimeInterval        { return self * 3600 }
 
-    public var day: NSTimeInterval          { return assertOneOrLess(days) }
-    public var days: NSTimeInterval         { return hours * hoursInDay }
+    public var day: NSTimeInterval          { return assertOne(days) }
+    public var days: NSTimeInterval         { return self * 3600 * 24 }
 }