From 1b02f78eee5b3ae7f1416d0f13a92d1fbca48ec2 Mon Sep 17 00:00:00 2001
From: kolaente <k@knt.li>
Date: Tue, 7 Oct 2025 10:55:13 +0200
Subject: [PATCH] fix(filter): check date boundary after timezone conversion

Resolves https://github.com/go-vikunja/vikunja/issues/1605
---
 pkg/models/task_collection_filter.go | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/pkg/models/task_collection_filter.go b/pkg/models/task_collection_filter.go
index 6d00f38df..8237b9281 100644
--- a/pkg/models/task_collection_filter.go
+++ b/pkg/models/task_collection_filter.go
@@ -89,9 +89,14 @@ func parseTimeFromUserInput(timeString string, loc *time.Location) (value time.T
 			return value, err
 		}
 		value = time.Date(year, time.Month(month), day, 0, 0, 0, 0, loc)
-		return value.In(config.GetTimeZone()), nil
 	}
-	return value.In(config.GetTimeZone()), err
+	value = value.In(config.GetTimeZone())
+	// Mysql/Mariadb does not support date values where the year < 1. To make this edge-case work,
+	// we're setting the year to 1 in that case. This must be done after timezone conversion.
+	if db.GetDialect() == builder.MYSQL && value.Year() < 1 {
+		value = value.AddDate(1-value.Year(), 0, 0)
+	}
+	return value, err
 }
 
 func parseFilterFromExpression(f fexpr.ExprGroup, loc *time.Location) (filter *taskFilter, err error) {
@@ -292,17 +297,17 @@ func getValueForField(field reflect.StructField, rawValue string, loc *time.Loca
 			t, err = datemath.Parse(rawValue)
 			if err == nil {
 				tt = t.Time(datemath.WithLocation(loc)).In(config.GetTimeZone())
+				// Mysql/Mariadb does not support date values where the year < 1. To make this edge-case work,
+				// we're setting the year to 1 in that case. This must be done after timezone conversion.
+				if db.GetDialect() == builder.MYSQL && tt.Year() < 1 {
+					tt = tt.AddDate(1-tt.Year(), 0, 0)
+				}
 			} else {
 				tt, err = parseTimeFromUserInput(rawValue, loc)
 			}
 			if err != nil {
 				return
 			}
-			// Mysql/Mariadb does not support date values where the year < 1. To make this edge-case work,
-			// we're setting the year to 1 in that case.
-			if db.GetDialect() == builder.MYSQL && tt.Year() < 1 {
-				tt = tt.AddDate(1-tt.Year(), 0, 0)
-			}
 			value = tt
 		}
 	case reflect.Slice: