Add comparator between two dates ignoring time

Foundation/NSDate.swift

@@ -196,6 +196,23 @@ extension NSDate {
     public func isEqualToDate(_ otherDate: NSDate) -> Bool {
         return timeIntervalSinceReferenceDate == otherDate.timeIntervalSinceReferenceDate
     }
+
+    public func isEqualToDateIgnoringTime(_ otherDate: NSDate) -> Bool {
+        let yearDayMonthComponents: NSCalendarUnit = [.Year, .Day, .Month]
+        let currentCalendar = NSCalendar.currentCalendar() // change to autoupdatingCurrentCalendar when it's implemented
+
+        let componentsFromSelf = currentCalendar.components( yearDayMonthComponents, fromDate: self);
+        let componentsFromOtherDate = currentCalendar.components( yearDayMonthComponents, fromDate: otherDate);
+
+        guard let unwrappedComponentsFromSelf = componentsFromSelf,
+              let unwrappedComponentsFromOtherDate = componentsFromOtherDate else {
+            return false
+        }
+
+        return ((unwrappedComponentsFromSelf.year == unwrappedComponentsFromOtherDate.year) &&
+            (unwrappedComponentsFromSelf.month == unwrappedComponentsFromOtherDate.month) &&
+            (unwrappedComponentsFromSelf.day == unwrappedComponentsFromOtherDate.day));
+    }
 }
 
 extension NSDate {

TestFoundation/TestNSDate.swift

@@ -35,6 +35,8 @@ class TestNSDate : XCTestCase {
             ("test_LaterDate", test_LaterDate),
             ("test_Compare", test_Compare),
             ("test_IsEqualToDate", test_IsEqualToDate),
+            ("test_IsEqualToDateIgnoringTime", test_IsEqualToDateIgnoringTime),
+
         ]
     }
 
@@ -114,4 +116,12 @@ class TestNSDate : XCTestCase {
         let d3 = d1.dateByAddingTimeInterval(ti)
         XCTAssertTrue(d2.isEqualToDate(d3))
     }
+
+    func test_IsEqualToDateIgnoringTime() {
+        let ti: NSTimeInterval = 1
+        let d1 = NSDate()
+        let d2 = d1.dateByAddingTimeInterval(ti)
+        let d3 = d2.dateByAddingTimeInterval(ti)
+        XCTAssertTrue(d2.isEqualToDateIgnoringTime(d3))
+    }
 }