diff --git a/apps/diaries/services.py b/apps/diaries/services.py
index e4210dc..27c2cea 100644
--- a/apps/diaries/services.py
+++ b/apps/diaries/services.py
@@ -3,21 +3,30 @@
     MESSAGE_LENGTH_WHICH_BRINGS_XP_IN_DIARY_COMMIT,
     STAR_FILLING_BONUS_VALUE,
     ADDITIONAL_XP_FOR_STAR_FILLING,
+    BANNED_WORDS_IN_MORE_DETAILED_MESSAGE,
 )
 
 from .models import DiaryCommit
 
 
+def has_commit_message_banned_words(message: str):
+    for word in BANNED_WORDS_IN_MORE_DETAILED_MESSAGE:
+        if word in message:
+            return True
+    return False
+
+
 def calculate_diary_commit_xp(commit: DiaryCommit):
     total_xp = [
         XP_PER_DAIRY_COMMIT,
     ]
 
     # additional xp for more detailed message
-    additional_xp_for_more_detailed_message = int(
-        len(commit.message) / MESSAGE_LENGTH_WHICH_BRINGS_XP_IN_DIARY_COMMIT
-    )
-    total_xp.append(additional_xp_for_more_detailed_message)
+    if not has_commit_message_banned_words(commit.message):
+        additional_xp_for_more_detailed_message = int(
+            len(commit.message) / MESSAGE_LENGTH_WHICH_BRINGS_XP_IN_DIARY_COMMIT
+        )
+        total_xp.append(additional_xp_for_more_detailed_message)
 
     # additional xp for star filling bonus
     if commit.diary.commits.count() == STAR_FILLING_BONUS_VALUE:
diff --git a/rp2/business_logic.py b/rp2/business_logic.py
index 06faacf..5e60f35 100644
--- a/rp2/business_logic.py
+++ b/rp2/business_logic.py
@@ -8,3 +8,7 @@
 
 # ===== RULES
 COMMIT_MIN_LENGTH = 10
+BANNED_WORDS_IN_MORE_DETAILED_MESSAGE = [
+    "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun",
+    "+0500", "Nov", "Dec", "Jan", "Feb", "Mar",
+]