3 files changed, 38 insertions, 18 deletions
diff --git a/src/c/fastforge_core.c b/src/c/fastforge_core.c
index 5254956..39d9ea8 100644
--- a/src/c/fastforge_core.c
+++ b/src/c/fastforge_core.c
@@ -61,24 +61,6 @@ static int compare_time_t_ascending(const void *a, const void *b) {
   return 0;
 }
 
-static time_t local_day_start(time_t timestamp) {
-  if (timestamp <= 0) {
-    return 0;
-  }
-
-  struct tm *tm_info = localtime(&timestamp);
-  if (!tm_info) {
-    return 0;
-  }
-
-  struct tm tm_copy = *tm_info;
-  tm_copy.tm_hour = 0;
-  tm_copy.tm_min = 0;
-  tm_copy.tm_sec = 0;
-  tm_copy.tm_isdst = -1;
-  return mktime(&tm_copy);
-}
-
 static bool is_next_local_day(time_t first_day, time_t second_day) {
   if (first_day <= 0 || second_day <= 0 || second_day < first_day) {
     return false;
diff --git a/src/c/fastforge_logic.c b/src/c/fastforge_logic.c
index b93240d..b8b44da 100644
--- a/src/c/fastforge_logic.c
+++ b/src/c/fastforge_logic.c
@@ -3,6 +3,25 @@
 #include <stdio.h>
 #include <time.h>
 
+#ifndef __struct_tm_defined
+#define FASTFORGE_TZ_LEN 6
+struct tm {
+  int tm_sec;
+  int tm_min;
+  int tm_hour;
+  int tm_mday;
+  int tm_mon;
+  int tm_year;
+  int tm_wday;
+  int tm_yday;
+  int tm_isdst;
+  int tm_gmtoff;
+  char tm_zone[FASTFORGE_TZ_LEN];
+};
+#endif
+struct tm *localtime(const time_t *timep);
+time_t mktime(struct tm *tb);
+
 time_t entry_duration_seconds(const FastEntry *entry) {
   if (!entry || entry->start_time == 0 || entry->end_time <= entry->start_time) {
     return 0;
@@ -55,6 +74,24 @@ void format_duration_hours_minutes(time_t seconds, char *buffer, size_t size) {
   snprintf(buffer, size, "%dh %02dm", hours, minutes);
 }
 
+time_t local_day_start(time_t timestamp) {
+  if (timestamp <= 0) {
+    return 0;
+  }
+
+  struct tm *tm_info = localtime(&timestamp);
+  if (!tm_info) {
+    return 0;
+  }
+
+  struct tm tm_copy = *tm_info;
+  tm_copy.tm_hour = 0;
+  tm_copy.tm_min = 0;
+  tm_copy.tm_sec = 0;
+  tm_copy.tm_isdst = -1;
+  return mktime(&tm_copy);
+}
+
 bool running_fast_is_at_target(const FastEntry *entry, time_t now) {
   if (!entry || entry->start_time == 0 || entry->end_time != 0 || entry->target_minutes == 0) {
     return false;
diff --git a/src/c/fastforge_logic.h b/src/c/fastforge_logic.h
index 7108da8..4ccaba7 100644
--- a/src/c/fastforge_logic.h
+++ b/src/c/fastforge_logic.h
@@ -12,6 +12,7 @@ uint8_t stage_level_for_elapsed(time_t elapsed_seconds);
 const char *stage_text_for_elapsed(time_t elapsed_seconds);
 void format_hhmmss(time_t seconds, char *buffer, size_t size);
 void format_duration_hours_minutes(time_t seconds, char *buffer, size_t size);
+time_t local_day_start(time_t timestamp);
 bool running_fast_is_at_target(const FastEntry *entry, time_t now);
 
 #endif