Change system time to snapshot time, so it won't be counted as expired

install.sh

@@ -2,11 +2,17 @@
 set -e
 set -x
 
+# set system time, so we can use snapshot packages
+DATETIME="20190201T000000Z"
+DATE=$(echo ${DATETIME} | cut -dT -f1)
+TIME=$(echo ${DATETIME} | cut -dT -f2)
+TIME="${TIME:0:2}:${TIME:2:2}:${TIME:4:2}"
+date +%Y%m%d -s "${DATE} ${TIME}"
+
 # use snapshot repos for deterministic package versions
-DATE="20190206T120000Z"
 cat << EOF > /etc/apt/sources.list
-deb http://snapshot.debian.org/archive/debian/${DATE}/ stretch main
-deb http://snapshot.debian.org/archive/debian-security/${DATE}/ stretch/updates main
+deb http://snapshot.debian.org/archive/debian/${DATETIME}/ stretch main
+deb http://snapshot.debian.org/archive/debian-security/${DATETIME}/ stretch/updates main
 EOF
 
 # update package sources