Sorry, I forgot to consider locales in my first patch. The attached updated patch also produces reproducible results if the locale is differing.
Regards, Reiner
diff --git a/debian/patches/build.patch b/debian/patches/build.patch
index b0bd0c8..298506d 100644
--- a/debian/patches/build.patch
+++ b/debian/patches/build.patch
@@ -18,7 +18,7 @@ Index: jquery/Makefile
VER = sed "s/@VERSION/${JQ_VER}/"
-DATE=$(shell git log -1 --pretty=format:%ad)
-+DATE=$(shell date)
++DATE=$(shell dpkg-parsechangelog -S Date | LC_ALL=C date -u -f -)
all: update_submodules core
signature.asc
Description: OpenPGP digital signature
