From ace2fce3a223122214c3b071809c3b34d12c27a5 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Sat, 25 Oct 2025 11:23:23 -0700
Subject: [PATCH] [core] Simplify ESPTime::strftime() and save 20 bytes flash

---
 esphome/core/time.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/esphome/core/time.h b/esphome/core/time.h
index 13a0127156..080a0793e0 100644
--- a/esphome/core/time.h
+++ b/esphome/core/time.h
@@ -46,6 +46,9 @@ struct ESPTime {
   /** Convert this ESPTime struct to a string as specified by the format argument.
    * @see https://en.cppreference.com/w/c/chrono/strftime
    *
+   * @warning This method returns a dynamically allocated string which can cause heap fragmentation with some
+   * microcontrollers.
+   *
    * @warning This method can return "ERROR" when the underlying strftime() call fails or when the
    * output exceeds 128 bytes.
    */