At some point there's an option with 15 may or 15 august, but as Bernard final statement "I didn't know but now know", he shoude choose from month with to numbers this month is July.

That's what I was leaning towards, but I still don't totally see it. More coffee.

Undisciplined

Yes now with help I found flaw in my calculations. The answer is Jule 16.

Bernard has to pairs on months with similar numbers:

When Bernard got information from Albert that he 100% should know the answer we take pair with unique number (May July), and it can't be May. So the answer is July 16

science

[Not-so-daily puzzle] Singapore at it, again

south_korea_ln

Yes now with help I found flaw in my calculations. The answer is Jule 16. 
Bernard has to pairs on months with similar numbers:
1) May July
2) July August

When Bernard got information from Albert that he 100% should know the answer we take pair with unique number (May July), and it can't be May. So the answer is July 16