From 7c54ff20d7bcb5a037a4ce45360cb24620628b1f Mon Sep 17 00:00:00 2001
From: Cupiditas <ligert123@hotmail.com>
Date: Fri, 4 Sep 2020 10:31:12 +1000
Subject: [PATCH 1/3] Added canonicalize for Periods

---
 stdlib/Dates/src/periods.jl | 1 +
 1 file changed, 1 insertion(+)

diff --git a/stdlib/Dates/src/periods.jl b/stdlib/Dates/src/periods.jl
index 529de24b80830..4ae2d8b908157 100644
--- a/stdlib/Dates/src/periods.jl
+++ b/stdlib/Dates/src/periods.jl
@@ -249,6 +249,7 @@ julia> Dates.canonicalize(Dates.CompoundPeriod(Dates.Minute(50000)))
 4 weeks, 6 days, 17 hours, 20 minutes
 ```
 """
+canonicalize(x::Period) = canonicalize(CompoundPeriod(x))
 function canonicalize(x::CompoundPeriod)
     # canonicalize Periods by pushing "overflow" into a coarser period.
     p = x.periods

From 63d0395ca7e4148b2bd51835f9ec61dd1d5da7c1 Mon Sep 17 00:00:00 2001
From: Cupiditas <ligert123@hotmail.com>
Date: Fri, 4 Sep 2020 13:06:53 +1000
Subject: [PATCH 2/3] Added tests for canonicalizing Periods

---
 stdlib/Dates/test/periods.jl | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/stdlib/Dates/test/periods.jl b/stdlib/Dates/test/periods.jl
index c93e7368f30d2..ddcd189ea45a4 100644
--- a/stdlib/Dates/test/periods.jl
+++ b/stdlib/Dates/test/periods.jl
@@ -378,6 +378,18 @@ end
     @test Dates.Date(2009, 2, 1) - (Dates.Month(1) + Dates.Day(1)) == Dates.Date(2008, 12, 31)
     @test_throws MethodError (Dates.Month(1) + Dates.Day(1)) - Dates.Date(2009,2,1)
 end
+
+@testset "canonicalize Period" begin
+    # reduce individual Period into most basic CompoundPeriod
+    @test Dates.canonicalize(Dates.Nanosecond(1000000)) == Dates.canonicalize(Dates.Millisecond(1))
+    @test Dates.canonicalize(Dates.Millisecond(1000)) == Dates.canonicalize(Dates.Second(1))
+    @test Dates.canonicalize(Dates.Second(60)) == Dates.canonicalize(Dates.Minute(1))
+    @test Dates.canonicalize(Dates.Minute(60)) == Dates.canonicalize(Dates.Hour(1))
+    @test Dates.canonicalize(Dates.Hour(24)) == Dates.canonicalize(Dates.Day(1))
+    @test Dates.canonicalize(Dates.Day(7)) == Dates.canonicalize(Dates.Week(1))
+    @test Dates.canonicalize(Dates.Month(12)) == Dates.canonicalize(Dates.Year(1))
+    @test Dates.canonicalize(Dates.Minute(24*60*1 + 12*60)) == Dates.canonicalize(Dates.CompoundPeriod([Dates.Day(1),Dates.Hour(12)]))
+end
 @testset "unary ops and vectorized period arithmetic" begin
     pa = [1y 1m 1w 1d; 1h 1mi 1s 1ms]
     cpa = [1y + 1s 1m + 1s 1w + 1s 1d + 1s; 1h + 1s 1mi + 1s 2m + 1s 1s + 1ms]
@@ -468,3 +480,4 @@ end
 end
 
 end
+

From 3482c013aa5242ab0f530f2ef41a5f2df6e790d1 Mon Sep 17 00:00:00 2001
From: Cupiditas <ligert123@hotmail.com>
Date: Sun, 6 Sep 2020 11:31:51 +1000
Subject: [PATCH 3/3] Added NEWS item for canonicalize addition

---
 NEWS.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/NEWS.md b/NEWS.md
index 98c68b32b7a26..4261dbacb485b 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -133,7 +133,7 @@ Standard library changes
 
 #### Dates
 * `Quarter` period is defined ([#35519]).
-
+* `canonicalize` can now take `Period` as an input ([#37391])
 #### Statistics