[time] Convert to C++17 nested namespace syntax (#12463)

esphome/components/time/automation.cpp

@@ -4,8 +4,7 @@
 
 #include <cinttypes>
 
-namespace esphome {
-namespace time {
+namespace esphome::time {
 
 static const char *const TAG = "automation";
 static const int MAX_TIMESTAMP_DRIFT = 900;  // how far can the clock drift before we consider
@@ -92,5 +91,4 @@ SyncTrigger::SyncTrigger(RealTimeClock *rtc) : rtc_(rtc) {
   rtc->add_on_time_sync_callback([this]() { this->trigger(); });
 }
 
-}  // namespace time
-}  // namespace esphome
+}  // namespace esphome::time

esphome/components/time/automation.h

@@ -8,8 +8,7 @@
 
 #include <vector>
 
-namespace esphome {
-namespace time {
+namespace esphome::time {
 
 class CronTrigger : public Trigger<>, public Component {
  public:
@@ -48,5 +47,4 @@ class SyncTrigger : public Trigger<>, public Component {
  protected:
   RealTimeClock *rtc_;
 };
-}  // namespace time
-}  // namespace esphome
+}  // namespace esphome::time

esphome/components/time/real_time_clock.cpp

@@ -17,8 +17,7 @@
 
 #include <cinttypes>
 
-namespace esphome {
-namespace time {
+namespace esphome::time {
 
 static const char *const TAG = "time";
 
@@ -78,5 +77,4 @@ void RealTimeClock::apply_timezone_() {
 }
 #endif
 
-}  // namespace time
-}  // namespace esphome
+}  // namespace esphome::time

esphome/components/time/real_time_clock.h

@@ -7,8 +7,7 @@
 #include "esphome/core/helpers.h"
 #include "esphome/core/time.h"
 
-namespace esphome {
-namespace time {
+namespace esphome::time {
 
 /// The RealTimeClock class exposes common timekeeping functions via the device's local real-time clock.
 ///
@@ -75,5 +74,4 @@ template<typename... Ts> class TimeHasTimeCondition : public Condition<Ts...> {
   RealTimeClock *parent_;
 };
 
-}  // namespace time
-}  // namespace esphome
+}  // namespace esphome::time