Punctuality is one of those words that have come to loose their meaning; atleast in the society that we dwell in.
Punctuality, as a lot of people have started to believe that it means being on time for work or being on time for school. But this is not the whole sphere and scope of this word but just a little aspect of it!
If you promise your friend to meet him / her at a particular time, make sure that you are there because that is punctuality too!
When you tell your mom that you will be back by a certain time, you have to be; not because of what you have promised and to whom you have made the promise but because that is inclusive in being punctual as well!
So if and when you know that you can not be at a certain place at a certain time, better not make that appointment and have the time changed to such you could abide to (Ofcourse that does not go for the time of your office and school ;)).