Change Time#date to return a Tuple of year, month, day instead of Time

spec/std/time/time_spec.cr

@@ -106,12 +106,17 @@ describe Time do
   describe ".local" do
     it "initializes" do
       t1 = Time.local 2002, 2, 25
+      t1.date.should eq({2002, 2, 25})
       t1.year.should eq(2002)
       t1.month.should eq(2)
       t1.day.should eq(25)
+      t1.hour.should eq(0)
+      t1.minute.should eq(0)
+      t1.second.should eq(0)
       t1.local?.should be_true
 
       t2 = Time.local 2002, 2, 25, 15, 25, 13, nanosecond: 8
+      t2.date.should eq({2002, 2, 25})
       t2.year.should eq(2002)
       t2.month.should eq(2)
       t2.day.should eq(25)

src/time.cr

@@ -741,13 +741,10 @@ struct Time
     )
   end
 
-  # Returns a copy of `self` with time-of-day components (hour, minute, second,
-  # nanoseconds) set to zero.
-  #
-  # This equals `at_beginning_of_day` or
-  # `Time.local(year, month, day, 0, 0, 0, nanoseconds: 0, location: location)`.
-  def date : Time
-    Time.local(year, month, day, location: location)
+  # Returns a `Tuple` with `year`, `month` and `day`.
+  def date : Tuple(Int32, Int32, Int32)
+    year, month, day, _ = year_month_day_day_year
+    {year, month, day}
   end
 
   # Returns the year of the proleptic Georgian Calendar (`0..9999`).