Use constant for daily flag offset

include/constants/flags.h

@@ -1566,6 +1566,7 @@
 #define FLAG_UNUSED_0x91F                           (SYSTEM_FLAGS + 0xBF) // Unused Flag
 
 // Daily Flags
+#define DAILY_FLAGS_START                           FLAG_DAILY_0x920
 #define FLAG_DAILY_0x920                            (SYSTEM_FLAGS + 0xC0)
 #define FLAG_DAILY_CONTEST_LOBBY_RECEIVED_BERRY     (SYSTEM_FLAGS + 0xC1)
 #define FLAG_DAILY_SECRET_BASE                      (SYSTEM_FLAGS + 0xC2)

src/event_data.c

@@ -48,7 +48,7 @@ void ClearTempFieldEventData(void)
 
 void ClearDailyFlags(void)
 {
-    memset(gSaveBlock1Ptr->flags + 0x124, 0, DAILY_FLAGS_SIZE);
+    memset(gSaveBlock1Ptr->flags + (DAILY_FLAGS_START / 8), 0, DAILY_FLAGS_SIZE);
 }
 
 void DisableNationalPokedex(void)