How to get human friendly format time zone offset (PHP) - php

Question

Help me to decide this task, please. (PHP, Symfony)
What I have:
List of time zone like
"Europe/Riga"
"Europe/Rome"
"Europe/Samara"
"Europe/San_Marino"
"Europe/Sarajevo"
In result I want to see:
(+00:00) Riga
(+01:30) Rome
(+03:00) Samara
(-01:00) San_Marino
(+05:00) Sarajevo
What I did:
$timeZoneIdentifierList = DateTimeZone::listIdentifiers();
$timeZoneUtc = new DateTimeZone('UTC');
$nowByUtc = new DateTime('now', $timeZoneUtc);
foreach ($timeZoneIdentifierList as $timeZoneIdentifier) {
$dateTimezoneItem = new DateTimeZone($timeZoneIdentifier);
$timeZone = $dateTimezoneItem->getOffset($nowByUtc);
$humanFriendlyOffset = $timeZone / 3600;
}
And if I dump $humanFriendlyOffset I get only digital value like this: 0, 1, -7, 2, 1.5
Question:
Is something prepared method in PHP/Symfony to convert
1 -> +01:00,
-7 -> -07:00,
2 -> +02:00,
1.5 -> +01:30
May be exist more easy way?

Answer 1

This solution creates a new DateTime object for each time zone.
$tzArr = ["Europe/Riga",
"Europe/Rome",
"Europe/Samara",
"Europe/San_Marino",
"Europe/Sarajevo",
"UTC"];
foreach($tzArr as $tz){
$dt = date_create('Now',new DateTimeZone($tz));
$formatTz = $dt->format('\(P\) e');
echo $formatTz."<br>\n";
}
Output:
(+02:00) Europe/Riga
(+01:00) Europe/Rome
(+04:00) Europe/Samara
(+01:00) Europe/San_Marino
(+01:00) Europe/Sarajevo
(+00:00) UTC
With a preg_replace the continent can be hidden and an output can be achieved exactly as desired.
foreach($tzArr as $tz){
$dt = date_create('Now',new DateTimeZone($tz));
$loc = preg_replace('~^[a-z]+/~i','', $dt->format('e'));
$formatTz = $dt->format('\(P\) ').$loc;
echo $formatTz."<br>\n";
}
Output:
(+02:00) Riga
(+01:00) Rome
(+04:00) Samara
(+01:00) San_Marino
(+01:00) Sarajevo
(+00:00) UTC

Answer 2

You can use the P formatter from DateTimeInterface::format to get a friendly timezone offset, but that's on a DateTime object, not a DateTimeZone object. So you could create a DateTime object, then explicitly set its timezone to the one you want, then get its offset. Something like this
$dt = new DateTime();
foreach (DateTimeZone::listIdentifiers() as $tz) {
$dt->setTimeZone(new DateTimeZone($tz));
printf("(%s) %s\n", $dt->format('P'), $tz);
}
Output:
(+00:00) Africa/Abidjan
(+00:00) Africa/Accra
(+03:00) Africa/Addis_Ababa
(+01:00) Africa/Algiers
(+03:00) Africa/Asmara
(+00:00) Africa/Bamako
(+01:00) Africa/Bangui
(+00:00) Africa/Banjul
(+00:00) Africa/Bissau