If you are on the Pill as a birth control measure, you must have a routine of when to take the daily pill: in the morning, at bedtime, etc. You are committed to this daily routine because you do not want to get pregnant.
But, do you have to take The Pill at the absolute same time every day? That depends on which Pill you are on, the combination (progestin and estrogen) or the Mini (progestin-only-Pill, or POP).
The combination Pill affords a bit more flexibility (a few hours), while the Mini-Pill is time-sensitive and missing it requires additional contraceptive measures. So, unless you are on that Mini-Pill, you don’t need to leave the party and rush home to take the daily pill at precisely 11pm — but do remember to take it as soon as you return home!
A recent article by Medical Daily – Birth Control for Women: Why You Should Take the Pill at the Same Time Every Day – explains it in details, and is worth reading.
Also, be reminded that the potency of the Pill may diminish with certain antibiotics, or if the pack was left in the heat (i.e. while going to the beach), requiring additional protection (condom, spermicidal gel or foam).
When in doubt, or if you have any questions, consult with your healthcare provider.