hi zer0fill.
Thank you for the suggestion.
The code of
$cal->server_TZ = date( 'Z' ) / 3600 ;
means there are many XOOPS which is set server_TZ
wrongly.
I didnot know this code is harmful.
I want to fix timezone/daylight problems, but it is not so soon.
When I'll try it, your suggestion must be useful for me.
p.s. Please tell me your server's time zone name.