diff --git a/esphome/core/scheduler.h b/esphome/core/scheduler.h
index 4633c202a0..68ad64b9b1 100644
--- a/esphome/core/scheduler.h
+++ b/esphome/core/scheduler.h
@@ -94,13 +94,16 @@ class Scheduler {
       char *dynamic_name;       // For allocated strings
     } name_;
     uint32_t interval;
-    // Split 64-bit time to handle millis() rollover. The scheduler combines the 32-bit millis()
-    // with a 16-bit rollover counter to create a 64-bit time that won't roll over for
-    // billions of years. This ensures correct scheduling even when devices run for months.
-    // Split into two fields for better memory alignment on 32-bit systems.
-    uint32_t next_execution_low_;  // Lower 32 bits of next execution time
+    // Split time to handle millis() rollover. The scheduler combines the 32-bit millis()
+    // with a 16-bit rollover counter to create a 48-bit time space (using 32+16 bits).
+    // This is intentionally limited to 48 bits, not stored as a full 64-bit value.
+    // With 49.7 days per 32-bit rollover, the 16-bit counter supports
+    // 49.7 days × 65536 = ~8900 years. This ensures correct scheduling
+    // even when devices run for months. Split into two fields for better memory
+    // alignment on 32-bit systems.
+    uint32_t next_execution_low_;  // Lower 32 bits of execution time (millis value)
     std::function<void()> callback;
-    uint16_t next_execution_high_;  // Upper 16 bits of next execution time
+    uint16_t next_execution_high_;  // Upper 16 bits (millis_major counter)
 
 #ifdef ESPHOME_THREAD_MULTI_ATOMICS
     // Multi-threaded with atomics: use atomic for lock-free access
@@ -154,7 +157,7 @@ class Scheduler {
     SchedulerItem &operator=(SchedulerItem &&) = delete;
 
     // Helper to get the name regardless of storage type
-    constexpr const char *get_name() const { return name_is_dynamic ? name_.dynamic_name : name_.static_name; }
+    const char *get_name() const { return name_is_dynamic ? name_.dynamic_name : name_.static_name; }
 
     // Helper to clear dynamic name if allocated
     void clear_dynamic_name() {
@@ -187,13 +190,17 @@ class Scheduler {
 
     static bool cmp(const std::unique_ptr<SchedulerItem> &a, const std::unique_ptr<SchedulerItem> &b);
 
-    // Helper methods to work with split execution time (constexpr for optimization)
+    // Note: We use 48 bits total (32 + 16), stored in a 64-bit value for API compatibility.
+    // The upper 16 bits of the 64-bit value are always zero, which is fine since
+    // millis_major_ is also 16 bits and they must match.
     constexpr uint64_t get_next_execution() const {
       return (static_cast<uint64_t>(next_execution_high_) << 32) | next_execution_low_;
     }
 
     constexpr void set_next_execution(uint64_t value) {
       next_execution_low_ = static_cast<uint32_t>(value);
+      // Cast to uint16_t intentionally truncates to lower 16 bits of the upper 32 bits.
+      // This is correct because millis_major_ that creates these values is also 16 bits.
       next_execution_high_ = static_cast<uint16_t>(value >> 32);
     }
     constexpr const char *get_type_str() const { return (type == TIMEOUT) ? "timeout" : "interval"; }