diff --git a/scripts/generate-modbus-register-doc.py b/scripts/generate-modbus-register-doc.py
index b2c960fd5..ce8c0010b 100644
--- a/scripts/generate-modbus-register-doc.py
+++ b/scripts/generate-modbus-register-doc.py
@@ -2,6 +2,10 @@ import fileinput
 import csv
 from itertools import groupby
 
+#
+# This is used to build the contents of the `Modbus-Entity-Registers.md` file used in the emsesp.org documentation.
+#
+
 # static data
 
 tag_to_tagtype = {
diff --git a/scripts/generate-modbus-register-doc.sh b/scripts/generate-modbus-register-doc.sh
index f034f7c65..863ddfb69 100644
--- a/scripts/generate-modbus-register-doc.sh
+++ b/scripts/generate-modbus-register-doc.sh
@@ -1,5 +1,7 @@
 #!/bin/bash
 
+# This is used to build the contents of the `Modbus-Entity-Registers.md` file used in the emsesp.org documentation.
+
 make clean
 make ARGS=-DEMSESP_STANDALONE
 echo "test entity_dump" | ./emsesp | python3 ./scripts/strip_csv.py | python3 ./scripts/generate-modbus-register-doc.py
diff --git a/scripts/generate_csv_and_headers.sh b/scripts/generate_csv_and_headers.sh
new file mode 100755
index 000000000..7d427b48b
--- /dev/null
+++ b/scripts/generate_csv_and_headers.sh
@@ -0,0 +1,56 @@
+#!/bin/sh
+
+#
+# Builds the dump CSV files, modbus headers and documentation.
+# To be run before a release with
+#   sh ./scripts/generate_csv_and_headers.sh
+#
+
+# build dummy modbus_entity_parameters.hpp  so it compiles
+cat >./src/modbus_entity_parameters.hpp <<EOL
+#include "modbus.h"
+#include "emsdevice.h"
+
+/*
+ * This file is auto-generated by the update_modbus_registers.sh script. Do not modify.
+*/
+
+// clang-format off
+
+namespace emsesp {
+
+using dt = EMSdevice::DeviceType;
+
+#define REGISTER_MAPPING(device_type, device_value_tag_type, long_name, modbus_register_offset, modbus_register_count) \\
+    { device_type, device_value_tag_type, long_name[0], modbus_register_offset, modbus_register_count }
+
+// IMPORTANT: This list MUST be ordered by keys "device_type", "device_value_tag_type" and "modbus_register_offset" in this order.
+const std::initializer_list<Modbus::EntityModbusInfo> Modbus::modbus_register_mappings = {};
+
+} // namespace emsesp
+
+// clang-format on
+
+EOL
+
+# build emsesp for standalone
+make clean
+make ARGS=-DEMSESP_STANDALONE
+
+# dump_entities.csv
+rm -f dump_entities.csv
+echo "test entity_dump" | ./emsesp | python3 ./scripts/strip_csv.py >dump_entities.csv
+ls -al dump_entities.csv
+
+# dump_telegrams.csv
+rm -f dump_telegrams.csv
+echo "test telegram_dump" | ./emsesp | python3 ./scripts/strip_csv.py >dump_telegrams.csv
+ls -al dump_telegrams.csv
+
+# generate ./src/modbus_entity_parameters.hpp
+rm -f ./src/modbus_entity_parameters.hpp
+cat dump_entities.csv | python3 ./scripts/update_modbus_registers.py >./src/modbus_entity_parameters.hpp
+ls -al ./src/modbus_entity_parameters.hpp
+
+# generate doc - Modbus-Entity-Registers.md used in the emsesp.org documentation.
+cat dump_entities.csv | python3 ./scripts/generate-modbus-register-doc.py >./docs/Modbus-Entity-Registers.md
diff --git a/scripts/update_modbus_registers.py b/scripts/update_modbus_registers.py
index 3df1c78f5..5495a9fd6 100644
--- a/scripts/update_modbus_registers.py
+++ b/scripts/update_modbus_registers.py
@@ -47,6 +47,7 @@ string_sizes = {
     "thermostat/switchtime1": 16,
     "thermostat/switchtime2": 16,
     "thermostat/switchtime": 16,
+    "thermostat/switchtimeww": 21,
     "controller/datetime": 25
 }
 
@@ -164,6 +165,7 @@ with fileinput.input() as f_input:
     for row in entities_reader:
         entity = {}
         for i, val in enumerate(row):
+            # print(headers[i] + ": " + val)
             entity[headers[i]] = val
         entities.append(entity)
 
@@ -196,8 +198,8 @@ for entity in entities:
             (-string_sizes[entity_dev_name] // 2)  # divide and round up
 
     if int(entity["modbus count"]) <= 0:
-        raise Exception('Entity "' + entity_shortname +
-                        '" does not have a size - string sizes need to be added manually to update_modbus_registers.py')
+        raise Exception('Entity "' + entity_dev_name + ' (' + entity_shortname + ')' +
+                        '" does not have a size - string sizes need to be added manually to update_modbus_registers.py/string_sizes')
 
     #    if entity["modbus count"] == "0":
     #        print("ignoring " + entity_dev_name + " - it has a register length of zero")