在我的网站中，每个用户在注册时都必须选择他们的时区。用户数据库表有一个名为timezone的列，其值是以下数组中的键之一：
$zones = array(
'UM12' => -12,
'UM11' => -11,
'UM10' => -10,
'UM95' => -9.5,
'UM9' => -9,
'UM8' => -8,
'UM7' => -7,
'UM6' => -6,
'UM5' => -5,
'UM45' => -4.5,
'UM4' => -4,
'UM35' => -3.5,
'UM3' => -3,
'UM2' => -2,
'UM1' => -1,
'UTC' => 0,
'UP1' => +1,
'UP2' => +2,
'UP3' => +3,
'UP35' => +3.5,
'UP4' => +4,
'UP45' => +4.5,
'UP5' => +5,
'UP55' => +5.5,
'UP575' => +5.75,
'UP6' => +6,
'UP65' => +6.5,
'UP7' => +7,
'UP8' => +8,
'UP875' => +8.75,
'UP9' => +9,
'UP95' => +9.5,
'UP10' => +10,
'UP105' => +10.5,
'UP11' => +11,
'UP115' => +11.5,
'UP12' => +12,
'UP1275' => +12.75,
'UP13' => +13,
'UP14' => +14
);
此外，Codeigniter为我提供了以下数组，但这没有太大帮助，因为它的值不能直接用于在PHP中创建DateTimeZone对象。
$lang['UM12'] = '(UTC -12:00) Baker/Howland Island';
$lang['UM11'] = '(UTC -11:00) Samoa Time Zone, Niue';
$lang['UM10'] = '(UTC -10:00) Hawaii-Aleutian Standard Time, Cook Islands, Tahiti';
$lang['UM95'] = '(UTC -9:30) Marquesas Islands';
$lang['UM9'] = '(UTC -9:00) Alaska Standard Time, Gambier Islands';
$lang['UM8'] = '(UTC -8:00) Pacific Standard Time, Clipperton Island';
$lang['UM7'] = '(UTC -7:00) Mountain Standard Time';
$lang['UM6'] = '(UTC -6:00) Central Standard Time';
$lang['UM5'] = '(UTC -5:00) Eastern Standard Time, Western Caribbean Standard Time';
$lang['UM45'] = '(UTC -4:30) Venezuelan Standard Time';
$lang['UM4'] = '(UTC -4:00) Atlantic Standard Time, Eastern Caribbean Standard Time';
$lang['UM35'] = '(UTC -3:30) Newfoundland Standard Time';
$lang['UM3'] = '(UTC -3:00) Argentina, Brazil, French Guiana, Uruguay';
$lang['UM2'] = '(UTC -2:00) South Georgia/South Sandwich Islands';
$lang['UM1'] = '(UTC -1:00) Azores, Cape Verde Islands';
$lang['UTC'] = '(UTC) Greenwich Mean Time, Western European Time';
$lang['UP1'] = '(UTC +1:00) Central European Time, West Africa Time';
$lang['UP2'] = '(UTC +2:00) Central Africa Time, Eastern European Time, Kaliningrad Time';
$lang['UP3'] = '(UTC +3:00) Moscow Time, East Africa Time';
$lang['UP35'] = '(UTC +3:30) Iran Standard Time';
$lang['UP4'] = '(UTC +4:00) Azerbaijan Standard Time, Samara Time';
$lang['UP45'] = '(UTC +4:30) Afghanistan';
$lang['UP5'] = '(UTC +5:00) Pakistan Standard Time, Yekaterinburg Time';
$lang['UP55'] = '(UTC +5:30) Indian Standard Time, Sri Lanka Time';
$lang['UP575'] = '(UTC +5:45) Nepal Time';
$lang['UP6'] = '(UTC +6:00) Bangladesh Standard Time, Bhutan Time, Omsk Time';
$lang['UP65'] = '(UTC +6:30) Cocos Islands, Myanmar';
$lang['UP7'] = '(UTC +7:00) Krasnoyarsk Time, Cambodia, Laos, Thailand, Vietnam';
$lang['UP8'] = '(UTC +8:00) Australian Western Standard Time, Beijing Time, Irkutsk Time';
$lang['UP875'] = '(UTC +8:45) Australian Central Western Standard Time';
$lang['UP9'] = '(UTC +9:00) Japan Standard Time, Korea Standard Time, Yakutsk Time';
$lang['UP95'] = '(UTC +9:30) Australian Central Standard Time';
$lang['UP10'] = '(UTC +10:00) Australian Eastern Standard Time, Vladivostok Time';
$lang['UP105'] = '(UTC +10:30) Lord Howe Island';
$lang['UP11'] = '(UTC +11:00) Magadan Time, Solomon Islands, Vanuatu';
$lang['UP115'] = '(UTC +11:30) Norfolk Island';
$lang['UP12'] = '(UTC +12:00) Fiji, Gilbert Islands, Kamchatka Time, New Zealand Standard Time';
$lang['UP1275'] = '(UTC +12:45) Chatham Islands Standard Time';
$lang['UP13'] = '(UTC +13:00) Phoenix Islands Time, Tonga';
$lang['UP14'] = '(UTC +14:00) Line Islands';
目前，Web服务器的default_timezone设置为UTC，数据库中所有日期时间值都采用mysql日期时间格式存储在此时区中。
因此，要根据用户的时区正确显示日期时间，我需要一种方法来进行转换。这是我到目前为止所得到的：
$timezone_offset=$zones[$user_row->timezone];
$utc_timestamp=strtotime($user_row->registered_on);
正如您所看到的，我需要一个以某种方式接受这两个参数的函数，并在用户的时区中给出日期时间。但我仍然无法弄清楚哪些功能对我的情况有用。
有人会介意给我一些建议吗？
非常感谢大家。
答案 0 :(得分：1)
http://www.php.net/manual/en/datetime.settimezone.php
<?php
$date = new DateTime('2000-01-01', new DateTimeZone('Pacific/Nauru'));
echo $date->format('Y-m-d H:i:sP') . "\n";
$date->setTimezone(new DateTimeZone('Pacific/Chatham'));
echo $date->format('Y-m-d H:i:sP') . "\n";
?>
同样适用于Codeigniter： http://codeigniter.com/user_guide/helpers/date_helper.html
gmt_to_local（）
采用Unix时间戳（引用 GMT）作为输入，并将其转换为 基于的本地化时间戳 时区和夏令时 提交。示例：$ timestamp = '1140153693'; $ timezone ='UM8'; $ daylight_saving = TRUE;
echo gmt_to_local($timestamp, $timezone, $daylight_saving);
答案 1 :(得分：1)
我所做的是创建一个新的timezones_string助手
function timezones_string($tz = '')
{
// Note: Don't change the order of these even though
// some items appear to be in the wrong order
$zones = array(
'UM12' => '-12:00',
'UM11' => '-11:00',
'UM10' => '-10:00',
'UM95' => '-9:30',
'UM9' => '-9:00',
'UM8' => '-8:00',
'UM7' => '-7:00',
'UM6' => '-6:00',
'UM5' => '-5:00',
'UM45' => '-4:30',
'UM4' => '-4:00',
'UM35' => '-3:30',
'UM3' => '-3:00',
'UM2' => '-2:00',
'UM1' => '-1:00',
'UTC' => '+0:00',
'UP1' => '+1:00',
'UP2' => '+2:00',
'UP3' => '+3:00',
'UP35' => '+3:30',
'UP4' => '+4:00',
'UP45' => '+4:30',
'UP5' => '+5:00',
'UP55' => '+5:30',
'UP575' => '+5:45',
'UP6' => '+6:00',
'UP65' => '+6:30',
'UP7' => '+7:00',
'UP8' => '+8:00',
'UP875' => '+8:45',
'UP9' => '+9:00',
'UP95' => '+9:30',
'UP10' => '+10:00',
'UP105' => '+10:30',
'UP11' => '+11:00',
'UP115' => '+11:30',
'UP12' => '+12:00',
'UP1275' => '+12:45',
'UP13' => '+13:00',
'UP14' => '+14:00',
);
if ($tz == '')
{
return $zones;
}
if ($tz == 'GMT')
$tz = 'UTC';
return ( ! isset($zones[$tz])) ? 0 : $zones[$tz];
}