Update app.py

app.py

@@ -15,7 +15,7 @@ def time_left_for_event(event:str, date:str)-> str: #it's import to specify the
     """A tool that calculates the time left for a certain event, and returns in a very convenient way the time between today and that events date
     Args:
         event: the event name, this can be wedding, birthday, trip, travel, work event, reunion, etc..
-        sate: the day of that event in calendar time
+        date: the day of that event in calendar time
 
     Returns:
         A string telling the user how many months, weeks or days are left before the event date