From fc86a8fd71e500bb931421c18f5f04cd92f43526 Mon Sep 17 00:00:00 2001
From: Timothy Moose <tim@swiftkick.it>
Date: Sun, 26 Jun 2022 19:49:18 -0500
Subject: [PATCH] Correct numerical errors in roundedFrameSection calculation

---
 Sources/JTAppleCalendar/JTACMonthQueryFunctions.swift | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Sources/JTAppleCalendar/JTACMonthQueryFunctions.swift b/Sources/JTAppleCalendar/JTACMonthQueryFunctions.swift
index c05bd5cf..a6449493 100644
--- a/Sources/JTAppleCalendar/JTACMonthQueryFunctions.swift
+++ b/Sources/JTAppleCalendar/JTACMonthQueryFunctions.swift
@@ -65,7 +65,11 @@ extension JTACMonthView {
         case .stopAtEachCalendarFrame, .stopAtEach, .nonStopTo:
             assert(fixedScrollSize != 0, "You should not try to divide by zero.")
             let frameSection = theTargetContentOffset / fixedScrollSize
-            let roundedFrameSection = floor(frameSection)
+            // Reduce the precision of `frameSection` before calling `floor()` to eliminate numerical
+            // errors that would produce the wrong result. For example, if `frameSection == 49.9999999999999`,
+            // the double precision calculation will incorrectly procude 49 while the float precision
+            // calculation will correctly produce 50.
+            let roundedFrameSection = CGFloat(floor(Float(frameSection)))
             if scrollDirection == .horizontal {
                 x = roundedFrameSection * fixedScrollSize
             } else {