Change PHP Timezones

When working with dates, PHP uses the system time by default, which is dependent on the timezone the server is in. So, instead of doing tricky math with the results of the date function, you can simply change the timezone.

Here is the function used to change the timezone:

<?php
putenv("TZ=US/Detroit");

One thing to keep in mind is that your MySQL will still be using the system time.

Here is a list of the timezone formats accepted in the above function:

AD    +4230+00131 Europe/Andorra
AE    +2518+05518 Asia/Dubai
AF    +3431+06912 Asia/Kabul
AG    +1703-06148 America/Antigua
AI    +1812-06304 America/Anguilla
AL    +4120+01950 Europe/Tirane
AM    +4011+04430 Asia/Yerevan
AN    +1211-06900 America/Curacao
AO    -0848+01314 Africa/Luanda
AQ    -7750+16636 Antarctica/McMurdo
AQ    -9000+00000 Antarctica/South_Pole
AQ    -6448-06406 Antarctica/Palmer
AQ    -6736+06253 Antarctica/Mawson
AQ    -6835+07758 Antarctica/Davis
AQ    -6617+11031 Antarctica/Casey
AQ    -6640+14001 Antarctica/DumontDUrville
AR    -3436-05827 America/Buenos_Aires
AR    -3257-06040 America/Rosario
AR    -3124-06411 America/Cordoba
AR    -2411-06518 America/Jujuy
AR    -2828-06547 America/Catamarca
AR    -3253-06849 America/Mendoza Mendoza
AS    -1416-17042 Pacific/Pago_Pago
AT    +4813+01620 Europe/Vienna
AU    -3133+15905 Australia/Lord_Howe
AU    -4253+14719 Australia/Hobart
AU    -3749+14458 Australia/Melbourne
AU    -3352+15113 Australia/Sydney
AU    -3157+14127 Australia/Broken_Hill
AU    -2728+15302 Australia/Brisbane
AU    -2016+14900 Australia/Lindeman
AU    -3455+13835 Australia/Adelaide
AU    -1228+13050 Australia/Darwin
AU    -3157+11551 Australia/Perth
AW    +1230-06858 America/Aruba
AZ    +4023+04951 Asia/Baku
BA    +4352+01825 Europe/Sarajevo
BB    +1306-05937 America/Barbados
BD    +2343+09025 Asia/Dacca
BE    +5050+00420 Europe/Brussels
BF    +1222-00131 Africa/Ouagadougou
BG    +4241+02319 Europe/Sofia
BH    +2623+05035 Asia/Bahrain
BI    -0323+02922 Africa/Bujumbura
BJ    +0629+00237 Africa/Porto-Novo
BM    +3217-06446 Atlantic/Bermuda
BN    +0456+11455 Asia/Brunei
BO    -1630-06809 America/La_Paz
BR    -0351-03225 America/Noronha
BR    -0127-04829 America/Belem
BR    -0343-03830 America/Fortaleza
BR    -0712-04812 America/Araguaina
BR    -0940-03543 America/Maceio
BR    -2332-04637 America/Sao_Paulo
BR    -1535-05605 America/Cuiaba
BR    -0846-06354 America/Porto_Velho
BR    -0308-06001 America/Manaus
BR    -0934-06731 America/Porto_Acre
BS    +2505-07721 America/Nassau
BT    +2728+08939 Asia/Thimbu
BW    -2545+02555 Africa/Gaborone
BY    +5354+02734 Europe/Minsk
BZ    +1730-08812 America/Belize
CA    +4734-05243 America/St_Johns
CA    +4439-06336 America/Halifax
CA    +4612-05957 America/Glace_Bay
CA    +5320-06025 America/Goose_Bay
CA    +6608-06544 America/Pangnirtung
CA    +4531-07334 America/Montreal
CA    +4901-08816 America/Nipigon
CA    +4823-08915 America/Thunder_Bay
CA    +6344-06828 America/Iqaluit
CA    +4953-09709 America/Winnipeg
CA    +4843-09429 America/Rainy_River
CA    +6245-09210 America/Rankin_Inlet
CA    +5024-10439 America/Regina
CA    +5017-10750 America/Swift_Current
CA    +5333-11328 America/Edmonton
CA    +6227-11421 America/Yellowknife
CA    +6825-11330 America/Inuvik
CA    +5946-12014 America/Dawson_Creek
CA    +4916-12307 America/Vancouver
CA    +6043-13503 America/Whitehorse
CA    +6404-13925 America/Dawson
CC    -1210+09655 Indian/Cocos
CD    -0418+01518 Africa/Kinshasa
CD    -1140+02728 Africa/Lubumbashi
CF    +0422+01835 Africa/Bangui
CG    -0416+01517 Africa/Brazzaville
CH    +4723+00832 Europe/Zurich
CI    +0519-00402 Africa/Abidjan
CK    -2114-15946 Pacific/Rarotonga
CL    -3327-07040 America/Santiago
CL    -2710-10927 Pacific/Easter
CM    +0403+00942 Africa/Douala
CN    +4545+12641 Asia/Harbin
CN    +3114+12128 Asia/Shanghai
CN    +2217+11409 Asia/Hong_Kong
CN    +2934+10635 Asia/Chungking
CN    +4348+08735 Asia/Urumqi
CN    +3929+07559 Asia/Kashgar
CO    +0436-07405 America/Bogota
CR    +0956-08405 America/Costa_Rica
CU    +2308-08222 America/Havana
CV    +1455-02331 Atlantic/Cape_Verde
CX    -1025+10543 Indian/Christmas
CY    +3510+03322 Asia/Nicosia
CZ    +5005+01426 Europe/Prague
DE    +5230+01322 Europe/Berlin
DJ    +1136+04309 Africa/Djibouti
DK    +5540+01235 Europe/Copenhagen
DM    +1518-06124 America/Dominica
DO    +1828-06954 America/Santo_Domingo
DZ    +3647+00303 Africa/Algiers
EC    -0210-07950 America/Guayaquil
EC    -0054-08936 Pacific/Galapagos
EE    +5925+02445 Europe/Tallinn
EG    +3003+03115 Africa/Cairo
EH    +2709-01312 Africa/El_Aaiun
ER    +1520+03853 Africa/Asmera
ES    +4024-00341 Europe/Madrid
ES    +3553-00519 Africa/Ceuta
ES    +2806-01524 Atlantic/Canary
ET    +0902+03842 Africa/Addis_Ababa
FI    +6010+02458 Europe/Helsinki
FJ    -1808+17825 Pacific/Fiji
FK    -5142-05751 Atlantic/Stanley
FM    +0931+13808 Pacific/Yap
FM    +0725+15147 Pacific/Truk
FM    +0658+15813 Pacific/Ponape
FM    +0519+16259 Pacific/Kosrae
FO    +6201-00646 Atlantic/Faeroe
FR    +4852+00220 Europe/Paris
GA    +0023+00927 Africa/Libreville
GB    +512830-0001845 Europe/London
GB    +5435-00555 Europe/Belfast
GD    +1203-06145 America/Grenada
GE    +4143+04449 Asia/Tbilisi
GF    +0456-05220 America/Cayenne
GH    +0533-00013 Africa/Accra
GI    +3608-00521 Europe/Gibraltar
GL    +7030-02215 America/Scoresbysund
GL    +6411-05144 America/Godthab
GL    +7634-06847 America/Thule
GM    +1328-01639 Africa/Banjul
GN    +0931-01343 Africa/Conakry
GP    +1614-06132 America/Guadeloupe
GQ    +0345+00847 Africa/Malabo
GR    +3758+02343 Europe/Athens
GS    -5416-03632 Atlantic/South_Georgia
GT    +1438-09031 America/Guatemala
GU    +1328+14445 Pacific/Guam
GW    +1151-01535 Africa/Bissau
GY    +0648-05810 America/Guyana
HN    +1406-08713 America/Tegucigalpa
HR    +4548+01558 Europe/Zagreb
HT    +1832-07220 America/Port-au-Prince
HU    +4730+01905 Europe/Budapest
ID    -0610+10648 Asia/Jakarta
ID    -0507+11924 Asia/Ujung_Pandang
ID    -0232+14042 Asia/Jayapura
IE    +5320-00615 Europe/Dublin
IL    +3146+03514 Asia/Jerusalem
IN    +2232+08822 Asia/Calcutta
IO    -0720+07225 Indian/Chagos
IQ    +3321+04425 Asia/Baghdad
IR    +3540+05126 Asia/Tehran
IS    +6409-02151 Atlantic/Reykjavik
IT    +4154+01229 Europe/Rome
JM    +1800-07648 America/Jamaica
JO    +3157+03556 Asia/Amman
JP    +353916+1394441 Asia/Tokyo
KE    -0117+03649 Africa/Nairobi
KG    +4254+07436 Asia/Bishkek
KH    +1133+10455 Asia/Phnom_Penh
KI    +0125+17300 Pacific/Tarawa
KI    -0308-17105 Pacific/Enderbury
KI    +0152-15720 Pacific/Kiritimati
KM    -1141+04316 Indian/Comoro
KN    +1718-06243 America/St_Kitts
KP    +3901+12545 Asia/Pyongyang
KR    +3733+12658 Asia/Seoul
KW    +2920+04759 Asia/Kuwait
KY    +1918-08123 America/Cayman
KZ    +4315+07657 Asia/Almaty
KZ    +5017+05710 Asia/Aqtobe
KZ    +4431+05016 Asia/Aqtau
LA    +1758+10236 Asia/Vientiane
LB    +3353+03530 Asia/Beirut
LC    +1401-06100 America/St_Lucia
LI    +4709+00931 Europe/Vaduz
LK    +0656+07951 Asia/Colombo
LR    +0618-01047 Africa/Monrovia
LS    -2928+02730 Africa/Maseru
LT    +5441+02519 Europe/Vilnius
LU    +4936+00609 Europe/Luxembourg
LV    +5657+02406 Europe/Riga
LY    +3254+01311 Africa/Tripoli
MA    +3339-00735 Africa/Casablanca
MC    +4342+00723 Europe/Monaco
MD    +4700+02850 Europe/Chisinau
MG    -1855+04731 Indian/Antananarivo
MH    +0709+17112 Pacific/Majuro
MH    +0905+16720 Pacific/Kwajalein
MK    +4159+02126 Europe/Skopje
ML    +1239-00800 Africa/Bamako
ML    +1446-00301 Africa/Timbuktu
MM    +1647+09610 Asia/Rangoon
MN    +4755+10653 Asia/Ulan_Bator
MO    +2214+11335 Asia/Macao
MP    +1512+14545 Pacific/Saipan
MQ    +1436-06105 America/Martinique
MR    +1806-01557 Africa/Nouakchott
MS    +1644-06213 America/Montserrat
MT    +3554+01431 Europe/Malta
MU    -2010+05730 Indian/Mauritius
MV    +0410+07330 Indian/Maldives
MW    -1547+03500 Africa/Blantyre
MX    +2105-08646 America/Cancun
MX    +1924-09909 America/Mexico_City
MX    +2313-10625 America/Mazatlan
MX    +2838-10605 America/Chihuahua
MX    +3152-11637 America/Ensenada
MX    +3232-11701 America/Tijuana
MY    +0310+10142 Asia/Kuala_Lumpur
MY    +0133+11020 Asia/Kuching
MZ    -2558+03235 Africa/Maputo
NA    -2234+01706 Africa/Windhoek
NC    -2216+16530 Pacific/Noumea
NE    +1331+00207 Africa/Niamey
NF    -2903+16758 Pacific/Norfolk
NG    +0627+00324 Africa/Lagos
NI    +1209-08617 America/Managua
NL    +5222+00454 Europe/Amsterdam
NO    +5955+01045 Europe/Oslo
NP    +2743+08519 Asia/Katmandu
NR    -0031+16655 Pacific/Nauru
NU    -1901+16955 Pacific/Niue
NZ    -3652+17446 Pacific/Auckland
NZ    -4355-17630 Pacific/Chatham
OM    +2336+05835 Asia/Muscat
PA    +0858-07932 America/Panama
PE    -1203-07703 America/Lima
PF    -1732-14934 Pacific/Tahiti
PF    -0900-13930 Pacific/Marquesas
PF    -2308-13457 Pacific/Gambier
PG    -0930+14710 Pacific/Port_Moresby
PH    +1435+12100 Asia/Manila
PK    +2452+06703 Asia/Karachi
PL    +5215+02100 Europe/Warsaw
PM    +4703-05620 America/Miquelon
PN    -2504-13005 Pacific/Pitcairn
PR    +182806-0660622 America/Puerto_Rico
PS    +3130+03428 Asia/Gaza
PT    +3843-00908 Europe/Lisbon
PT    +3238-01654 Atlantic/Madeira
PT    +3744-02540 Atlantic/Azores
PW    +0720+13429 Pacific/Palau
PY    -2516-05740 America/Asuncion
QA    +2517+05132 Asia/Qatar
RE    -2052+05528 Indian/Reunion
RO    +4426+02606 Europe/Bucharest
RU    +5443+02030 Europe/Kaliningrad
RU    +5545+03735 Europe/Moscow
RU    +5312+05009 Europe/Samara
RU    +5651+06036 Asia/Yekaterinburg
RU    +5500+07324 Asia/Omsk
RU    +5502+08255 Asia/Novosibirsk
RU    +5601+09250 Asia/Krasnoyarsk
RU    +5216+10420 Asia/Irkutsk
RU    +6200+12940 Asia/Yakutsk
RU    +4310+13156 Asia/Vladivostok
RU    +5934+15048 Asia/Magadan
RU    +5301+15839 Asia/Kamchatka
RU    +6445+17729 Asia/Anadyr
RW    -0157+03004 Africa/Kigali
SA    +2438+04643 Asia/Riyadh
SB    -0932+16012 Pacific/Guadalcanal
SC    -0440+05528 Indian/Mahe
SD    +1536+03232 Africa/Khartoum
SE    +5920+01803 Europe/Stockholm
SG    +0117+10351 Asia/Singapore
SH    -1555-00542 Atlantic/St_Helena
SI    +4603+01431 Europe/Ljubljana
SJ    +7800+01600 Arctic/Longyearbyen
SJ    +7059-00805 Atlantic/Jan_Mayen
SK    +4809+01707 Europe/Bratislava
SL    +0830-01315 Africa/Freetown
SM    +4355+01228 Europe/San_Marino
SN    +1440-01726 Africa/Dakar
SO    +0204+04522 Africa/Mogadishu
SR    +0550-05510 America/Paramaribo
ST    +0020+00644 Africa/Sao_Tome
SV    +1342-08912 America/El_Salvador
SY    +3330+03618 Asia/Damascus
SZ    -2618+03106 Africa/Mbabane
TC    +2128-07108 America/Grand_Turk
TD    +1207+01503 Africa/Ndjamena
TF    -492110+0701303 Indian/Kerguelen
TG    +0608+00113 Africa/Lome
TH    +1345+10031 Asia/Bangkok
TJ    +3835+06848 Asia/Dushanbe
TK    -0922-17114 Pacific/Fakaofo
TM    +3757+05823 Asia/Ashkhabad
TN    +3648+01011 Africa/Tunis
TO    -2110+17510 Pacific/Tongatapu
TR    +4101+02858 Europe/Istanbul
TT    +1039-06131 America/Port_of_Spain
TV    -0831+17913 Pacific/Funafuti
TW    +2503+12130 Asia/Taipei
TZ    -0648+03917 Africa/Dar_es_Salaam
UA    +5026+03031 Europe/Kiev
UA    +4457+03406 Europe/Simferopol
UG    +0019+03225 Africa/Kampala
UM    +1700-16830 Pacific/Johnston
UM    +2813-17722 Pacific/Midway
UM    +1917+16637 Pacific/Wake
US    +404251-0740023 America/New_York
US    +421953-0830245 America/Detroit
US    +381515-0854534 America/Louisville
US    +394606-0860929 America/Indianapolis
US    +382232-0862041 America/Indiana/Marengo
US    +411745-0863730 America/Indiana/Knox
US    +384452-0850402 America/Indiana/Vevay
US    +415100-0873900 America/Chicago
US    +450628-0873651 America/Menominee
US    +394421-1045903 America/Denver
US    +433649-1161209 America/Boise
US    +364708-1084111 America/Shiprock
US    +332654-1120424 America/Phoenix
US    +340308-1181434 America/Los_Angeles
US    +611305-1495401 America/Anchorage
US    +581807-1342511 America/Juneau
US    +593249-1394338 America/Yakutat
US    +643004-1652423 America/Nome
US    +515248-1763929 America/Adak
US    +211825-1575130 Pacific/Honolulu
UY    -3453-05611 America/Montevideo
UZ    +3940+06648 Asia/Samarkand
UZ    +4120+06918 Asia/Tashkent
VA    +4154+01227 Europe/Vatican
VC    +1309-06114 America/St_Vincent
VE    +1030-06656 America/Caracas
VG    +1827-06437 America/Tortola
VI    +1821-06456 America/St_Thomas
VN    +1045+10640 Asia/Saigon
VU    -1740+16825 Pacific/Efate
WF    -1318-17610 Pacific/Wallis
WS    -1350-17144 Pacific/Apia
YE    +1245+04512 Asia/Aden
YT    -1247+04514 Indian/Mayotte
YU    +4450+02030 Europe/Belgrade
ZA    -2615+02800 Africa/Johannesburg
ZM    -1525+02817 Africa/Lusaka
ZW    -1750+03103 Africa/Harare
Tags: #php
Thomas Hunter II Avatar

Thomas is the author of Advanced Microservices and is a prolific public speaker with a passion for reducing complex problems into simple language and diagrams. His career includes working at Fortune 50's in the Midwest, co-founding a successful startup, and everything in between.