Add timezone class

source/Timezone.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace Proper;
+
+use DateTimeZone;
+
+class Timezone {
+    public static function utc_timezone(): DateTimeZone {
+        return new DateTimeZone( 'UTC' );
+    }
+
+    public static function utc_offset(): string {
+        return '+00:00';
+    }
+
+    public static function site_timezone(): DateTimeZone {
+        $timezone_string = get_option( 'timezone_string' );
+
+        if ( $timezone_string ) {
+            return new DateTimeZone( $timezone_string );
+        } else {
+            return new DateTimeZone( self::site_offset() );
+        }
+    }
+
+    // Will return an offset using the WordPress timezone set by the user
+    // Example return values: -04:00, +00:00, or +5:45
+    public static function site_offset(): string {
+        // Start with the offset such as -4, 0, or 5.75
+        $offset_number = (float) get_option( 'gmt_offset' );
+
+        // Build a string to represent the offset such as -04:00, +00:00, or +5:45
+        $result = '';
+
+        // Start with either - or +
+        $result .= $offset_number < 0 ? '-' : '+';
+
+        $whole_part  = abs( $offset_number );
+        $hour_part   = floor( $whole_part );
+        $minute_part = $whole_part - $hour_part;
+
+        $hours   = strval( $hour_part );
+        $minutes = strval( $minute_part * 60 );
+
+        // Add hour part to result
+        $result .= str_pad( $hours, 2, '0', STR_PAD_LEFT );
+
+        // Add separator
+        $result .= ':';
+
+        // Add minute part to result
+        $result .= str_pad( $minutes, 2, '0', STR_PAD_LEFT );
+
+        return $result;
+    }
+}

tests/TimezoneTest.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Proper;
+
+use DateTimeZone;
+
+class TimezoneTest extends \WP_UnitTestCase {
+    protected function setUp(): void {
+        delete_option('timezone_string', 'America/New_York');
+    }
+
+    public function test_utc_timezone() {
+        $this->assertEquals( new DateTimeZone( 'UTC' ), Timezone::utc_timezone() );
+    }
+
+    public function test_utc_offset() {
+        $this->assertEquals( '+00:00', Timezone::utc_offset() );
+    }
+
+    public function test_site_timezone() {
+        update_option('timezone_string', 'America/New_York');
+        $this->assertEquals(new DateTimeZone('America/New_York'), Timezone::site_timezone());
+    }
+    public function test_site_offset() {
+        update_option('timezone_string', 'America/New_York');
+        $this->assertEquals('-04:00', Timezone::site_offset());
+    }
+
+    public function test_site_timezone_with_offset_timezone() {
+        update_option('gmt_offset', '8.75');
+        $this->assertEquals(new DateTimeZone('+08:45'), Timezone::site_timezone());
+    }
+
+    public function test_site_offset_with_offset_timezone() {
+        update_option('gmt_offset', '8.75');
+        $this->assertEquals('+08:45', Timezone::site_offset());
+    }
+}