I have no idea, why the wrong answer has so many up-votes and is chosen as the best one :D
The answer is - NO.
Statistics on official Tibia website gets updated once per day on 3:00 AM, exatly 1 hour before TibiaBosses stats, so simple conclusion is that there is no possibility to check which boss was killed this day, until stats updates.
Worth to mention that stats shows kills from the last 24 hours/from the whole week.
Example:
Someone killed the boss at 11.00 AM on Monday - using official stats from tibia.com you will know it about 3.00 AM on Tuesday. The only case when you can know bosses killed in the same day is:
- when your friend killed it and told you about it
- when you can see the death body
- when boss spawned between 00.00 - 3.00 - then yes, official stats will show it in the same day :P