From eceb097cc7b6801e9041bb3ebcf9b1874bc47e41 Mon Sep 17 00:00:00 2001
From: proddy <paul@derbyshire.nl>
Date: Sun, 28 Jun 2026 16:08:31 +0200
Subject: [PATCH] fix thermostat date/time for HT3

---
 CHANGELOG_LATEST.md        | 3 ++-
 src/devices/thermostat.cpp | 5 ++++-
 src/emsesp_version.h       | 2 +-
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG_LATEST.md b/CHANGELOG_LATEST.md
index f47f825d9..991434ef8 100644
--- a/CHANGELOG_LATEST.md
+++ b/CHANGELOG_LATEST.md
@@ -13,7 +13,8 @@ For more details go to [emsesp.org](https://emsesp.org/).
 - signed value for solarInfuence [#3077](https://github.com/emsesp/EMS-ESP32/issues/3077)
 - set bin file upload limit to 1M again [3086](https://github.com/emsesp/EMS-ESP32/issues/3086)
 - check arithmetric operations on strings [#3127](https://github.com/emsesp/EMS-ESP32/discussions/3127)
-- Fix: Prevent system crash during WiFi network discovery on ESP32-S3 hardware [#3128](https://github.com/emsesp/EMS-ESP32/pull/3128)
+- prevent system crash during WiFi network discovery on ESP32-S3 hardware [#3128](https://github.com/emsesp/EMS-ESP32/pull/3128)
+- fix setting date/time on Junkers thermostats
 
 ## Changed
 
diff --git a/src/devices/thermostat.cpp b/src/devices/thermostat.cpp
index 8f5441cc3..3cbfec93d 100644
--- a/src/devices/thermostat.cpp
+++ b/src/devices/thermostat.cpp
@@ -3070,7 +3070,6 @@ bool Thermostat::set_datetime(const char * value, const int8_t id) {
         data[6] = (tm_->tm_wday + 6) % 7;            // Bosch counts from Mo, time from Su
         data[7] = (id == 0) ? 2 : tm_->tm_isdst + 2; // set DST and flag for ext. clock
         if (model() == EMSdevice::EMS_DEVICE_FLAG_JUNKERS) {
-            data[6]++; // Junkers use 1-7;
             data[7] = 0;
         }
     } else if (dt.length() == 23) {
@@ -3094,6 +3093,10 @@ bool Thermostat::set_datetime(const char * value, const int8_t id) {
         return false;
     }
 
+    if (model() == EMSdevice::EMS_DEVICE_FLAG_JUNKERS) {
+        data[6]++; // Junkers use 1-7 for day of the week
+    }
+
     // LOG_INFO("Setting date and time: %02d.%02d.2%03d-%02d:%02d:%02d-%d-%d", data[3], data[1], data[0], data[2], data[4], data[5], data[6], data[7]);
     write_command(EMS_TYPE_time, 0, data, 8, EMS_TYPE_time);
 
diff --git a/src/emsesp_version.h b/src/emsesp_version.h
index 74e1e397b..3928edd22 100644
--- a/src/emsesp_version.h
+++ b/src/emsesp_version.h
@@ -1 +1 @@
-#define EMSESP_APP_VERSION "3.8.3-dev.7"
+#define EMSESP_APP_VERSION "3.8.3-dev.8"