PHP如何获取当前时间

<?php
date_default_timezone_set('Asia/Shanghai');//此句用于消除时间差
echo $nowtime=date("Y-n-j H:i:s");
?>

显示的格式: 年-月-日 小时:分钟:秒

相关时间参数:

a - "am" 或是 "pm"
A - "AM" 或是 "PM"
d - 几日，二位数字，若不足二位则前面补零; 如: "01" 至 "31"
D - 星期几，三个英文字母; 如: "Fri"
F - 月份，英文全名; 如: "January"
h - 12 小时制的小时; 如: "01" 至 "12"
H - 24 小时制的小时; 如: "00" 至 "23"
g - 12 小时制的小时，不足二位不补零; 如: "1" 至 12"
G - 24 小时制的小时，不足二位不补零; 如: "0" 至 "23"
i - 分钟; 如: "00" 至 "59"
j - 几日，二位数字，若不足二位不补零; 如: "1" 至 "31"
l - 星期几，英文全名; 如: "Friday"
m - 月份，二位数字，若不足二位则在前面补零; 如: "01" 至 "12"
n - 月份，二位数字，若不足二位则不补零; 如: "1" 至 "12"
M - 月份，三个英文字母; 如: "Jan"
s - 秒; 如: "00" 至 "59"
S - 字尾加英文序数，二个英文字母; 如: "th"，"nd"
t - 指定月份的天数; 如: "28" 至 "31"
U - 总秒数
w - 数字型的星期几，如: "0" (星期日) 至 "6" (星期六)
Y - 年，四位数字; 如: "1999"
y - 年，二位数字; 如: "99"
z - 一年中的第几天; 如: "0" 至 "365"

相关时区:

Africa/Abidjan	Africa/Accra	Africa/Addis_Ababa	Africa/Algiers	Africa/Asmera
Africa/Bamako	Africa/Bangui	Africa/Banjul	Africa/Bissau	Africa/Blantyre
Africa/Brazzaville	Africa/Bujumbura	Africa/Cairo	Africa/Casablanca	Africa/Ceuta
Africa/Conakry	Africa/Dakar	Africa/Dar_es_Salaam	Africa/Djibouti	Africa/Douala
Africa/El_Aaiun	Africa/Freetown	Africa/Gaborone	Africa/Harare	Africa/Johannesburg
Africa/Kampala	Africa/Khartoum	Africa/Kigali	Africa/Kinshasa	Africa/Lagos
Africa/Libreville	Africa/Lome	Africa/Luanda	Africa/Lubumbashi	Africa/Lusaka
Africa/Malabo	Africa/Maputo	Africa/Maseru	Africa/Mbabane	Africa/Mogadishu
Africa/Monrovia	Africa/Nairobi	Africa/Ndjamena	Africa/Niamey	Africa/Nouakchott
Africa/Ouagadougou	Africa/Porto-Novo	Africa/Sao_Tome	Africa/Timbuktu	Africa/Tripoli
Africa/Tunis	Africa/Windhoek

Asia/Aden	Asia/Almaty	Asia/Amman	Asia/Anadyr	Asia/Aqtau
Asia/Aqtobe	Asia/Ashgabat	Asia/Ashkhabad	Asia/Baghdad	Asia/Bahrain
Asia/Baku	Asia/Bangkok	Asia/Beirut	Asia/Bishkek	Asia/Brunei
Asia/Calcutta	Asia/Choibalsan	Asia/Chongqing	Asia/Chungking	Asia/Colombo
Asia/Dacca	Asia/Damascus	Asia/Dhaka	Asia/Dili	Asia/Dubai
Asia/Dushanbe	Asia/Gaza	Asia/Harbin	Asia/Hong_Kong	Asia/Hovd
Asia/Irkutsk	Asia/Istanbul	Asia/Jakarta	Asia/Jayapura	Asia/Jerusalem
Asia/Kabul	Asia/Kamchatka	Asia/Karachi	Asia/Kashgar	Asia/Katmandu
Asia/Krasnoyarsk	Asia/Kuala_Lumpur	Asia/Kuching	Asia/Kuwait	Asia/Macao
Asia/Macau	Asia/Magadan	Asia/Makassar	Asia/Manila	Asia/Muscat
Asia/Nicosia	Asia/Novosibirsk	Asia/Omsk	Asia/Oral	Asia/Phnom_Penh
Asia/Pontianak	Asia/Pyongyang	Asia/Qatar	Asia/Qyzylorda	Asia/Rangoon
Asia/Riyadh	Asia/Saigon	Asia/Sakhalin	Asia/Samarkand	Asia/Seoul
Asia/Shanghai	Asia/Singapore	Asia/Taipei	Asia/Tashkent	Asia/Tbilisi
Asia/Tehran	Asia/Tel_Aviv	Asia/Thimbu	Asia/Thimphu	Asia/Tokyo
Asia/Ujung_Pandang	Asia/Ulaanbaatar	Asia/Ulan_Bator	Asia/Urumqi	Asia/Vientiane
Asia/Vladivostok	Asia/Yakutsk	Asia/Yekaterinburg	Asia/Yerevan

Europe/Amsterdam	Europe/Andorra	Europe/Athens	Europe/Belfast	Europe/Belgrade
Europe/Berlin	Europe/Bratislava	Europe/Brussels	Europe/Bucharest	Europe/Budapest
Europe/Chisinau	Europe/Copenhagen	Europe/Dublin	Europe/Gibraltar	Europe/Guernsey
Europe/Helsinki	Europe/Isle_of_Man	Europe/Istanbul	Europe/Jersey	Europe/Kaliningrad
Europe/Kiev	Europe/Lisbon	Europe/Ljubljana	Europe/London	Europe/Luxembourg
Europe/Madrid	Europe/Malta	Europe/Mariehamn	Europe/Minsk	Europe/Monaco
Europe/Moscow	Europe/Nicosia	Europe/Oslo	Europe/Paris	Europe/Prague
Europe/Riga	Europe/Rome	Europe/Samara	Europe/San_Marino	Europe/Sarajevo
Europe/Simferopol	Europe/Skopje	Europe/Sofia	Europe/Stockholm	Europe/Tallinn
Europe/Tirane	Europe/Tiraspol	Europe/Uzhgorod	Europe/Vaduz	Europe/Vatican
Europe/Vienna	Europe/Vilnius	Europe/Volgograd	Europe/Warsaw	Europe/Zagreb
Europe/Zaporozhye	Europe/Zurich

Brazil/Acre	Brazil/DeNoronha	Brazil/East	Brazil/West	Canada/Atlantic
Canada/Central	Canada/East-Saskatchewan	Canada/Eastern	Canada/Mountain	Canada/Newfoundland
Canada/Pacific	Canada/Saskatchewan	Canada/Yukon	CET	Chile/Continental
Chile/EasterIsland	CST6CDT	Cuba	EET	Egypt
Eire	EST	EST5EDT	Etc/GMT	Etc/GMT+0
Etc/GMT+1	Etc/GMT+10	Etc/GMT+11	Etc/GMT+12	Etc/GMT+2
Etc/GMT+3	Etc/GMT+4	Etc/GMT+5	Etc/GMT+6	Etc/GMT+7
Etc/GMT+8	Etc/GMT+9	Etc/GMT-0	Etc/GMT-1	Etc/GMT-10
Etc/GMT-11	Etc/GMT-12	Etc/GMT-13	Etc/GMT-14	Etc/GMT-2
Etc/GMT-3	Etc/GMT-4	Etc/GMT-5	Etc/GMT-6	Etc/GMT-7
Etc/GMT-8	Etc/GMT-9	Etc/GMT0	Etc/Greenwich	Etc/UCT
Etc/Universal	Etc/UTC	Etc/Zulu	Factory	GB
GB-Eire	GMT	GMT+0	GMT-0	GMT0
Greenwich	Hongkong	HST	Iceland	Iran
Israel	Jamaica	Japan	Kwajalein	Libya
MET	Mexico/BajaNorte	Mexico/BajaSur	Mexico/General	MST
MST7MDT	Navajo	NZ	NZ-CHAT	Poland
Portugal	PRC	PST8PDT	ROC	ROK
Singapore	Turkey	UCT	Universal	US/Alaska
US/Aleutian	US/Arizona	US/Central	US/East-Indiana	US/Eastern
US/Hawaii	US/Indiana-Starke	US/Michigan	US/Mountain	US/Pacific
US/Pacific-New	US/Samoa	UTC	W-SU	WET
Zulu