php日期格式化不起作用

Question

$t = DateTime::createFromFormat('Gi', '900');
$time_str = $t->format('gi a');
echo $time_str; //outputs 600 pm instead of 9am. Why? and How do I get 9am?

I am not sure where I am going wrong.. I am following what is given here in terms of date formatting: http://php.net/manual/en/function.date.php

Thanks!

Answer 1

The documentation you linked is for the date() function. The DateTime::createFromFormat is not the same (though the format strings are pretty much identical).

I expect the format parsing is having trouble recognizing the difference between the hour and minute components.

If you split them up with a space, you get the desired result:

$t = DateTime::createFromFormat('G i', '9 00');
$time_str = $t->format('gi a');
echo $time_str;
// Output is 900 am

Edit:

The inability for PHP to parse a format string like Gi is a known bug . The parser for G doesn't know whether to read 9 or 90 and in the latter case that 90 is too high.

Answer 2

As i said in my comment this works :

$t = DateTime::createFromFormat('G i', '9 00');
$time_str = $t->format('gi a');
echo $time_str.PHP_EOL;

Cannot find any where written down - but suspect the time needs to be separated ... either by space or colon or something else