Punctuality is the characteristic of being able to complete a required task or fulfill an obligation before or at a previously designated time. "Punctual" is often used synonymously with "on time." Punctual can also, when talking about grammar, mean to be accurate.
According to each culture, there is often an understanding about what is considered an acceptable degree of punctuality. Usually, a small amount of lateness is acceptable; this is commonly about ten or fifteen minutes in Western cultures. In some cultures, such as Japanese society, or in the military there basically is no allowance.
Some cultures have an unspoken understanding that actual deadlines are different from stated deadlines; for example, it may be understood in a particular culture that people will turn up an hour later than advertised. In this case, since everyone understands that a 9 am meeting will actually start around 10 am, no one is inconvenienced when everyone turns up at 10 am.
In cultures which value punctuality, being late is tantamount to showing disrespect for another's time and may be considered insulting. In such cases, punctuality may be enforced by social penalties, for example by excluding low-status latecomers from meetings entirely. Such considerations can lead on to considering the value of punctuality in econometrics and to considering the effects of non-punctuality on others in queueing theory.