diff -urEbwB tigervnc-1.13.1.orig/java/CMakeLists.txt tigervnc-1.13.1/java/CMakeLists.txt
--- tigervnc-1.13.1.orig/java/CMakeLists.txt	2024-09-26 22:41:57.677131737 +0200
+++ tigervnc-1.13.1/java/CMakeLists.txt	2024-09-26 22:46:01.029014276 +0200
@@ -139,6 +139,15 @@
 string(REGEX REPLACE "jar" "" Java_PATH ${Java_JAR_EXECUTABLE})
 string(REGEX REPLACE ".exe" "" Java_PATH ${Java_PATH})
 
+if (DEFINED ENV{SOURCE_DATE_EPOCH})
+    execute_process(
+      COMMAND "date" "-u" "-d" "@$ENV{SOURCE_DATE_EPOCH}" "+%Y-%m-%dT%H:%M:%SZ"
+      OUTPUT_VARIABLE COMPILATION_DATE
+      OUTPUT_STRIP_TRAILING_WHITESPACE)
+else ()
+    STRING(TIMESTAMP COMPILATION_DATE "+%Y-%m-%dT%H:%M:%SZ")
+endif ()
+
 add_custom_command(OUTPUT VncViewer.jar
   DEPENDS ${JAVA_CLASSES}
     ${SRCDIR}/${CLASSPATH}/MANIFEST.MF
@@ -148,8 +157,10 @@
     ${BINDIR}/${CLASSPATH}/insecure.png
     ${BINDIR}/${CLASSPATH}/secure.png
   COMMAND ${JAVA_ARCHIVE}
-  ARGS cfm VncViewer.jar
-    ${SRCDIR}/${CLASSPATH}/MANIFEST.MF
+  ARGS --create
+    --date=${COMPILATION_DATE}
+    --file=VncViewer.jar
+    --manifest=${SRCDIR}/${CLASSPATH}/MANIFEST.MF
     ${CLASSPATH}/timestamp
     ${CLASSPATH}/*.class
     com/tigervnc/rfb/*.class