In respect of timezone, there is a difference between PHP5 version and operating systems and the process environment.
 strftime() generates E_NOTICE/E_STRICT/E_WARNING if the process doesn't have its own timezone settings.
 Under old Windows, if the format includes multi-byte strings, the parse is stopped within the string.
Re: Nucleus CMS 4.0の開発に関して
To keep the consistency of datetime, the expression of timestamp should be based on UTC and its time differences. Then we don't mind the server environments.