diff --git a/Tusker/Extensions/Date+TimeAgo.swift b/Tusker/Extensions/Date+TimeAgo.swift
index bca179dd..bce334e2 100644
--- a/Tusker/Extensions/Date+TimeAgo.swift
+++ b/Tusker/Extensions/Date+TimeAgo.swift
@@ -10,11 +10,11 @@ import Foundation
 
 extension Date {
 
+    private static let unitFlags = Set<Calendar.Component>([.second, .minute, .hour, .day, .weekOfYear, .month, .year])
+    
     func timeAgo() -> (Int, Calendar.Component) {
         let calendar = NSCalendar.current
-        let unitFlags = Set<Calendar.Component>([.second, .minute, .hour, .day, .weekOfYear, .month, .year])
-        
-        let components = calendar.dateComponents(unitFlags, from: self, to: Date())
+        let components = calendar.dateComponents(Date.unitFlags, from: self, to: Date())
         
         if components.year! >= 1 {
             return (components.year!, .year)