From 33f79577a16f56629ddf9c1f1034259da7222d9c Mon Sep 17 00:00:00 2001
From: Take Weiland <diesieben07@gmail.com>
Date: Sat, 4 Mar 2023 04:16:04 +0100
Subject: [PATCH] Fix Interval#count counting the endpoint as part of the
 interval (#1308)

* Fix Interval#count counting the endpoint as part of the interval
Fixes #1306

* Run formatter
---
 src/interval.js            | 2 +-
 test/interval/info.test.js | 7 ++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/interval.js b/src/interval.js
index a4c177ae6..33caf6d4d 100644
--- a/src/interval.js
+++ b/src/interval.js
@@ -240,7 +240,7 @@ export default class Interval {
     if (!this.isValid) return NaN;
     const start = this.start.startOf(unit),
       end = this.end.startOf(unit);
-    return Math.floor(end.diff(start, unit).get(unit)) + 1;
+    return Math.floor(end.diff(start, unit).get(unit)) + (end.valueOf() !== this.end.valueOf());
   }
 
   /**
diff --git a/test/interval/info.test.js b/test/interval/info.test.js
index 466f0961c..9be5510a8 100644
--- a/test/interval/info.test.js
+++ b/test/interval/info.test.js
@@ -54,9 +54,14 @@ test("Interval#count('years') returns 2 if the interval crosses the new year", (
   expect(i.count("years")).toBe(2);
 });
 
+test("Interval#count() does not count the endpoint of the interval", () => {
+  const i = DateTime.fromISO("2022-10-01").until(DateTime.fromISO("2022-10-03"));
+  expect(i.count("days")).toBe(2);
+});
+
 test("Interval#count() uses milliseconds by default", () => {
   const i = DateTime.fromISO("2016-05-25T03:00").until(DateTime.fromISO("2016-05-25T14:00"));
-  expect(i.count()).toBe(39600001);
+  expect(i.count()).toBe(39600000);
 });
 
 test("Interval#count() returns NaN for invalid intervals", () => {