note 8620 added to Funciones de fecha y hora

Getting used to work with UNIX timestamps is not difficult. A timestamp is just a computer-friendly form of representing a moment in time. It simply consists in the number of seconds elapsed from the midnight of Jan-1-1970 which is called the "Epoch" or Unix Epoch. In PHP you'll get this number by calling the time(); function. Now that you have this number you can use it for a variety of porpuses, mainly querying for human-friendly information such as name of the day, name of month, hour, minutes, seconds, year, etc. You get that info for your locale (e.g. your local language if not english) using the strfmktime() function. The opposite (getting the timestamp from the "easy" parameters like hour, minute, second, month, day, year, etc) is done calling the mktime() function. These 3 functions are the ones you'll be using the most of the time and there is lots of nice things you will be able to do combining the three. A fourth function you'll find very useful is checkdate(), so now you can validate dates so you avoid 31th of April or February 30th. If you're working with databases timestamps are very useful. They only require standard integer numbers and allow you to very different later views since you can query lots of information from this numbers. In PostgreSQL I use int4 data types to save them. So check'em out. Don't miss them :) http://www.php.net/manual/es/ref.datetime.php