There is a major difference between subjective and objective time. The former is a sense created by cultural norms and personal sensations. The time to go to bed or leave the party is not set in stone. The latter is generally imposed by outside forces. We are told when the movie begins, the plane flies, and TV program starts. Communication issues arise when the two types of time are not in synch. In such a case, if you want people to arrive wedding by the objective deadline, you have to take into account their subjective clock. This manipulation is a very common throughout the world.
The hosts of social events make certain assumptions about their guests and play with the time. For example, in Israel, if they want to all the guests to arrive by 8:30, they will write on the invitation that the hupa (wedding ceremony) is at 7:00. If they wrote the actual time, many of the guests would arrive at 9:30. In South Africa, for example, the suggested and actual time would be identical if not very close. Another example is dinner time. In some South American countries, the meal at a dinner party is very late, almost 11:00, because guests leave quite soon after the meal. If the host wants a long party, it is necessary to delay the meal. The timing involved in dating is quite complicated. It is advisable to arrive little early to a first date but only for the purpose of checking out the "merchandise." So, even there, the formal time is not the actual time of arrival.
Family life also has its chronological challenges. Children have almost no sense of actual time. Parents spending a day at the park with their children often say that they are leaving in five minutes when they actually mean 15 minutes. If they told the truth, it would take 30 minutes, if not longer. Children understand the subjective meaning, i.e. quite soon as compared to in a little while, much better than the formal meaning. A common translation issue between couples is the phrase I am ready before leaving the house. Most men express this when they are standing by the door with keys in hand, that is ready right now. Most women say this when they are personally ready and about to start closing the house, that is in a least five minutes. Time and language have a complicated relation.
There are situations where circumstances require people to be on time, which is quite a challenge even for some adults. Airlines strongly recommend that you arrive early so as to avoid unpleasant scene. Tour bus drivers, knowing their customers, take extreme measures to guarantee punctuality. One driver in Las Vegas informed the passengers of the exact cost of a taxi from Hoover Dam to Los Vegas. He let everybody know when he was leaving the bus stop at the former. The amount was so prohibitive that nobody was late. As a final example, I had a friend in Portland, OR, Bob, who had zero sense of time but a good sense of humor. On one occasion, we needed him to show up on time. Since he lived rather close, we told him to drop whatever he was doing some twenty minutes before the agreed time and driver over immediately. He actually showed up on time but with a towel over his midsection and said "I was taking a shower." We got to the event on time.
The purpose of communication is to be understood. A statement is a lie or exaggeration only if the receiver takes it literally. Such is the case with time. As long as everybody understands each other, all is fair in setting the time.