[time] Add `USE_TIME_TIMEZONE` define (#9290)

esphome/components/time/__init__.py

@@ -268,7 +268,19 @@ def validate_tz(value: str) -> str:
 
 TIME_SCHEMA = cv.Schema(
     {
-        cv.Optional(CONF_TIMEZONE, default=detect_tz): validate_tz,
+        cv.SplitDefault(
+            CONF_TIMEZONE,
+            esp8266=detect_tz,
+            esp32=detect_tz,
+            rp2040=detect_tz,
+            bk72xx=detect_tz,
+            rtl87xx=detect_tz,
+            ln882x=detect_tz,
+            host=detect_tz,
+        ): cv.All(
+            cv.only_with_framework(["arduino", "esp-idf", "host"]),
+            validate_tz,
+        ),
         cv.Optional(CONF_ON_TIME): automation.validate_automation(
             {
                 cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(CronTrigger),
@@ -293,7 +305,9 @@ TIME_SCHEMA = cv.Schema(
 
 
 async def setup_time_core_(time_var, config):
-    cg.add(time_var.set_timezone(config[CONF_TIMEZONE]))
+    if timezone := config.get(CONF_TIMEZONE):
+        cg.add(time_var.set_timezone(timezone))
+        cg.add_define("USE_TIME_TIMEZONE")
 
     for conf in config.get(CONF_ON_TIME, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], time_var)

esphome/components/time/real_time_clock.cpp

@@ -35,8 +35,10 @@ void RealTimeClock::synchronize_epoch_(uint32_t epoch) {
     ret = settimeofday(&timev, nullptr);
   }
 
+#ifdef USE_TIME_TIMEZONE
   // Move timezone back to local timezone.
   this->apply_timezone_();
+#endif
 
   if (ret != 0) {
     ESP_LOGW(TAG, "setimeofday() failed with code %d", ret);
@@ -49,10 +51,12 @@ void RealTimeClock::synchronize_epoch_(uint32_t epoch) {
   this->time_sync_callback_.call();
 }
 
+#ifdef USE_TIME_TIMEZONE
 void RealTimeClock::apply_timezone_() {
   setenv("TZ", this->timezone_.c_str(), 1);
   tzset();
 }
+#endif
 
 }  // namespace time
 }  // namespace esphome

esphome/components/time/real_time_clock.h

@@ -20,6 +20,7 @@ class RealTimeClock : public PollingComponent {
  public:
   explicit RealTimeClock();
 
+#ifdef USE_TIME_TIMEZONE
   /// Set the time zone.
   void set_timezone(const std::string &tz) {
     this->timezone_ = tz;
@@ -28,6 +29,7 @@ class RealTimeClock : public PollingComponent {
 
   /// Get the time zone currently in use.
   std::string get_timezone() { return this->timezone_; }
+#endif
 
   /// Get the time in the currently defined timezone.
   ESPTime now() { return ESPTime::from_epoch_local(this->timestamp_now()); }
@@ -46,8 +48,10 @@ class RealTimeClock : public PollingComponent {
   /// Report a unix epoch as current time.
   void synchronize_epoch_(uint32_t epoch);
 
+#ifdef USE_TIME_TIMEZONE
   std::string timezone_{};
   void apply_timezone_();
+#endif
 
   CallbackManager<void()> time_sync_callback_;
 };

esphome/core/defines.h

@@ -116,6 +116,7 @@
 #define USE_OTA_PASSWORD
 #define USE_OTA_STATE_CALLBACK
 #define USE_OTA_VERSION 2
+#define USE_TIME_TIMEZONE
 #define USE_WIFI
 #define USE_WIFI_AP
 #define USE_WIREGUARD