diff --git a/projectforge-business/src/main/kotlin/org/projectforge/birthdaybutler/BirthdayButlerService.kt b/projectforge-business/src/main/kotlin/org/projectforge/birthdaybutler/BirthdayButlerService.kt
index 3762dbb27c..e4d42cd55d 100644
--- a/projectforge-business/src/main/kotlin/org/projectforge/birthdaybutler/BirthdayButlerService.kt
+++ b/projectforge-business/src/main/kotlin/org/projectforge/birthdaybutler/BirthdayButlerService.kt
@@ -133,7 +133,7 @@ class BirthdayButlerService {
         month,
         locale
       )
-    }_${LocalDateTime.now().year}.docx"
+    }_${getYear(month)}.docx"
   }
 
   /**
@@ -206,7 +206,7 @@ class BirthdayButlerService {
       if (birthdayList.isNotEmpty()) {
         val variables = Variables()
         variables.put("table", "") // Marker for finding table (should be removed).
-        variables.put("year", LocalDateTime.now().year)
+        variables.put("year", getYear(month))
         variables.put("month", translateMonth(month, locale = locale))
         val birthdayButlerTemplate = configurationService.getOfficeTemplateFile("BirthdayButlerTemplate.docx")
         check(birthdayButlerTemplate != null) { "BirthdayButlerTemplate.docx not found" }
@@ -320,6 +320,25 @@ class BirthdayButlerService {
       return StringHelper.format2DigitNumber(number)
     }
 
+    /**
+     * Returns the year for the given month. If the month more than 2 months is in the past, the next year is returned.
+     */
+    private fun getYear(month: Month): Int {
+      return getYear(month, LocalDateTime.now().month)
+    }
+
+    /**
+     * Only for testing purposes
+     */
+    internal fun getYear(month: Month, currentMonth: Month): Int {
+      return if (month.ordinal + 2 < currentMonth.ordinal) {
+        // At the end of the year, the next year is meant.
+        LocalDateTime.now().year + 1
+      } else {
+        return LocalDateTime.now().year
+      }
+    }
+
     private val months = arrayOf(
       "calendar.month.january",
       "calendar.month.february",
diff --git a/projectforge-business/src/test/kotlin/org/projectforge/birthdaybutler/BithdayButlerServiceTest.kt b/projectforge-business/src/test/kotlin/org/projectforge/birthdaybutler/BithdayButlerServiceTest.kt
new file mode 100644
index 0000000000..f166134c93
--- /dev/null
+++ b/projectforge-business/src/test/kotlin/org/projectforge/birthdaybutler/BithdayButlerServiceTest.kt
@@ -0,0 +1,55 @@
+/////////////////////////////////////////////////////////////////////////////
+//
+// Project ProjectForge Community Edition
+//         www.projectforge.org
+//
+// Copyright (C) 2001-2024 Micromata GmbH, Germany (www.micromata.com)
+//
+// ProjectForge is dual-licensed.
+//
+// This community edition is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as published
+// by the Free Software Foundation; version 3 of the License.
+//
+// This community edition is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+// Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, see http://www.gnu.org/licenses/.
+//
+/////////////////////////////////////////////////////////////////////////////
+
+package org.projectforge.birthdaybutler
+
+import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.Test
+import java.time.LocalDateTime
+import java.time.Month
+
+class BithdayButlerServiceTest {
+  @Test
+  fun testGetYear() {
+    val year = LocalDateTime.now().year
+    testGetYear(currentMonth = Month.JANUARY, month = Month.JANUARY, year)
+    testGetYear(currentMonth = Month.JANUARY, month = Month.DECEMBER, year)
+    testGetYear(currentMonth = Month.FEBRUARY, month = Month.JANUARY, year)
+    testGetYear(currentMonth = Month.FEBRUARY, month = Month.FEBRUARY, year)
+    testGetYear(currentMonth = Month.FEBRUARY, month = Month.DECEMBER, year)
+    testGetYear(currentMonth = Month.JUNE, month = Month.JANUARY, year + 1)
+    testGetYear(currentMonth = Month.JUNE, month = Month.MARCH, year + 1)
+    testGetYear(currentMonth = Month.JUNE, month = Month.APRIL, year)
+    testGetYear(currentMonth = Month.JUNE, month = Month.MAY, year)
+    testGetYear(currentMonth = Month.JUNE, month = Month.DECEMBER, year)
+    testGetYear(currentMonth = Month.DECEMBER, month = Month.JANUARY, year + 1)
+    testGetYear(currentMonth = Month.DECEMBER, month = Month.SEPTEMBER, year + 1)
+    testGetYear(currentMonth = Month.DECEMBER, month = Month.OCTOBER, year)
+    testGetYear(currentMonth = Month.DECEMBER, month = Month.NOVEMBER, year)
+    testGetYear(currentMonth = Month.DECEMBER, month = Month.DECEMBER, year)
+  }
+
+  private fun testGetYear(currentMonth: Month, month: Month, expectedYear: Int) {
+    Assertions.assertEquals(expectedYear, BirthdayButlerService.getYear(month, currentMonth))
+  }
+}