What delay in taking the contraceptive pill affects its effectiveness?

Do daily delays in taking the hormonal contraceptive pill - Vibin reduce its effectiveness? My fixed time is 7:30 p.m. but sometimes it will happen with a pill at 6:30 p.m. and sometimes at 11 p.m. However, these differences in time never exceed 12 hours. Another question is whether if I once drank a tablet with a sweet milk drink, was it properly absorbed and contraception was not lowered? Thanks in advance for your reply