Difference between 24:00 and 00:00?

Question

What is the difference between 24:00 clock and 00:00 clock. IMO 24:00 clock is the day before and 00:00 clock is the beginning of the new day. But I'm not really convinced and I'm new to date programming

Update: Here is what wikipedia article say about military time and style guide about how to deal with 24:00 and 00:00 confusion: http://en.m.wikipedia.org/wiki/24-hour_clock#section_1.

Answer 1

There is no 24:00. It's just that PHP understands when you input 24:00, instead of throwing an error, or returning false (like before 5.3). If you tell PHP 24:00 today, it will understand 00:00 tomorrow. And they're both the same moment in PHP's time representation.

You can tell PHP it's 24:00, but when you ask PHP, it will always say 00:00. 24:00 is just another way of saying 00:00 the following day. There is no zero-length extra second (or something) between 23:59 and 00:00.

So, I don't understand when you say you can't schedule something for every Saturday at midnight, while you actually have two ways to schedule that: Fri 24:00 or Sat 00:00. No reason for using Sat 00:01.

Answer 2

After 23:59 comes 0:00, not 24:00 Please see the code below, in php, as you put the 'php' tag:

echo date('G:i:s', mktime(0,0,0)) . "\n" ;
echo date('G:i:s', mktime(0,0,0)-1) . "\n" ;

It will display:

0:00:00
23:59:59