feat: add database session timezone configuration

app/Config/Database.php

@@ -49,6 +49,7 @@ class Database extends Config
             'datetime' => 'Y-m-d H:i:s',
             'time'     => 'H:i:s',
         ],
+        'timezone' => false,
     ];
 
     //    /**
@@ -98,6 +99,7 @@ class Database extends Config
     //            'datetime' => 'Y-m-d H:i:s',
     //            'time'     => 'H:i:s',
     //        ],
+    //        'timezone'   => false,
     //    ];
 
     //    /**
@@ -155,6 +157,7 @@ class Database extends Config
     //            'datetime' => 'Y-m-d H:i:s',
     //            'time'     => 'H:i:s',
     //        ],
+    //        'timezone'   => false,
     //    ];
 
     /**

system/Database/BaseConnection.php

@@ -16,6 +16,8 @@
 use Closure;
 use CodeIgniter\Database\Exceptions\DatabaseException;
 use CodeIgniter\Events\Events;
+use CodeIgniter\I18n\Time;
+use Exception;
 use stdClass;
 use Stringable;
 use Throwable;
@@ -156,6 +158,20 @@ abstract class BaseConnection implements ConnectionInterface
      */
     protected $DBCollat = '';
 
+    /**
+     * Database session timezone
+     *
+     * false    = Don't set timezone (default, backward compatible)
+     * true     = Automatically sync with app timezone
+     * string   = Specific timezone (offset or named timezone)
+     *
+     * Named timezones (e.g., 'America/New_York') will be automatically
+     * converted to offsets (e.g., '-05:00') for database compatibility.
+     *
+     * @var bool|string
+     */
+    protected $timezone = false;
+
     /**
      * Swap Prefix
      *
@@ -1915,6 +1931,68 @@ protected function _enableForeignKeyChecks()
         return '';
     }
 
+    /**
+     * Converts a named timezone to an offset string.
+     *
+     * Converts timezone identifiers (e.g., 'America/New_York') to offset strings
+     * (e.g., '-05:00' or '-04:00' depending on DST). This is useful because not all
+     * databases have timezone tables loaded, but all support offset notation.
+     *
+     * @param string $timezone Named timezone (e.g., 'America/New_York', 'UTC', 'Europe/Paris')
+     *
+     * @return string Offset string (e.g., '+00:00', '-05:00', '+01:00')
+     */
+    protected function convertTimezoneToOffset(string $timezone): string
+    {
+        // If it's already an offset, return as-is
+        if (preg_match('/^[+-]\d{2}:\d{2}$/', $timezone)) {
+            return $timezone;
+        }
+
+        try {
+            $offset = Time::now($timezone)->getOffset();
+
+            // Convert offset seconds to +-HH:MM format
+            $hours   = (int) ($offset / 3600);
+            $minutes = abs((int) (($offset % 3600) / 60));
+
+            return sprintf('%+03d:%02d', $hours, $minutes);
+        } catch (Exception $e) {
+            // If timezone conversion fails, log and return UTC
+            log_message('error', "Invalid timezone '{$timezone}': {$e->getMessage()}. Falling back to UTC.");
+
+            return '+00:00';
+        }
+    }
+
+    /**
+     * Gets the timezone string to use for database session.
+     *
+     * Handles the timezone configuration logic:
+     * - false: Don't set timezone (returns null)
+     * - true: Auto-sync with app timezone from config
+     * - string: Use specific timezone (converts named timezones to offsets)
+     *
+     * @return string|null The timezone offset string, or null if timezone should not be set
+     */
+    protected function getSessionTimezone(): ?string
+    {
+        if ($this->timezone === false) {
+            return null;
+        }
+
+        // Auto-sync with app timezone
+        if ($this->timezone === true) {
+            $appConfig = config('App');
+            $timezone  = $appConfig->appTimezone ?? 'UTC';
+        } else {
+            // Use specific timezone from config
+            $timezone = $this->timezone;
+        }
+
+        return $this->convertTimezoneToOffset($timezone);
+    }
+
     /**
      * Accessor for properties if they exist.
      *

system/Database/MySQLi/Connection.php

@@ -123,27 +123,38 @@ public function connect(bool $persistent = false)
             $this->mysqli->options(MYSQLI_OPT_INT_AND_FLOAT_NATIVE, 1);
         }
 
+        // Build init command for strictOn and timezone
+        $initCommands = [];
+
         if ($this->strictOn !== null) {
             if ($this->strictOn) {
-                $this->mysqli->options(
-                    MYSQLI_INIT_COMMAND,
-                    "SET SESSION sql_mode = CONCAT(@@sql_mode, ',', 'STRICT_ALL_TABLES')",
-                );
+                $initCommands[] = "sql_mode = CONCAT(@@sql_mode, ',', 'STRICT_ALL_TABLES')";
             } else {
-                $this->mysqli->options(
-                    MYSQLI_INIT_COMMAND,
-                    "SET SESSION sql_mode = REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
-                                        @@sql_mode,
-                                        'STRICT_ALL_TABLES,', ''),
-                                    ',STRICT_ALL_TABLES', ''),
-                                'STRICT_ALL_TABLES', ''),
-                            'STRICT_TRANS_TABLES,', ''),
-                        ',STRICT_TRANS_TABLES', ''),
-                    'STRICT_TRANS_TABLES', '')",
-                );
+                $initCommands[] = "sql_mode = REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
+                                    @@sql_mode,
+                                    'STRICT_ALL_TABLES,', ''),
+                                ',STRICT_ALL_TABLES', ''),
+                            'STRICT_ALL_TABLES', ''),
+                        'STRICT_TRANS_TABLES,', ''),
+                    ',STRICT_TRANS_TABLES', ''),
+                'STRICT_TRANS_TABLES', '')";
             }
         }
 
+        // Set session timezone if configured
+        $timezoneOffset = $this->getSessionTimezone();
+        if ($timezoneOffset !== null) {
+            $initCommands[] = "time_zone = '{$timezoneOffset}'";
+        }
+
+        // Set init command if we have any commands
+        if ($initCommands !== []) {
+            $this->mysqli->options(
+                MYSQLI_INIT_COMMAND,
+                'SET SESSION ' . implode(', ', $initCommands),
+            );
+        }
+
         if (is_array($this->encrypt)) {
             $ssl = [];
 

system/Database/OCI8/Connection.php

@@ -145,9 +145,19 @@ public function connect(bool $persistent = false)
 
         $func = $persistent ? 'oci_pconnect' : 'oci_connect';
 
-        return ($this->charset === '')
+        $this->connID = ($this->charset === '')
             ? $func($this->username, $this->password, $this->DSN)
             : $func($this->username, $this->password, $this->DSN, $this->charset);
+
+        // Set session timezone if configured and connection is successful
+        if ($this->connID !== false) {
+            $timezoneOffset = $this->getSessionTimezone();
+            if ($timezoneOffset !== null) {
+                $this->simpleQuery("ALTER SESSION SET TIME_ZONE = '{$timezoneOffset}'");
+            }
+        }
+
+        return $this->connID;
     }
 
     /**

system/Database/Postgre/Connection.php

@@ -97,6 +97,12 @@ public function connect(bool $persistent = false)
 
                 throw new DatabaseException($error);
             }
+
+            // Set session timezone if configured
+            $timezoneOffset = $this->getSessionTimezone();
+            if ($timezoneOffset !== null) {
+                $this->simpleQuery("SET TIME ZONE '{$timezoneOffset}'");
+            }
         }
 
         return $this->connID;

tests/system/Database/BaseConnectionTest.php

@@ -345,4 +345,93 @@ public static function provideEscapeIdentifier(): iterable
             'with dots' => ['com.sitedb.web', '"com.sitedb.web"'],
         ];
     }
+
+    public function testConvertTimezoneToOffsetWithOffset(): void
+    {
+        $db = new MockConnection($this->options);
+
+        // Offset strings should be returned as-is
+        $result = $this->getPrivateMethodInvoker($db, 'convertTimezoneToOffset')('+05:30');
+        $this->assertSame('+05:30', $result);
+
+        $result = $this->getPrivateMethodInvoker($db, 'convertTimezoneToOffset')('-08:00');
+        $this->assertSame('-08:00', $result);
+
+        $result = $this->getPrivateMethodInvoker($db, 'convertTimezoneToOffset')('+00:00');
+        $this->assertSame('+00:00', $result);
+    }
+
+    public function testConvertTimezoneToOffsetWithNamedTimezone(): void
+    {
+        $db = new MockConnection($this->options);
+
+        // UTC should always be +00:00
+        $result = $this->getPrivateMethodInvoker($db, 'convertTimezoneToOffset')('UTC');
+        $this->assertSame('+00:00', $result);
+
+        $result = $this->getPrivateMethodInvoker($db, 'convertTimezoneToOffset')('America/New_York');
+        $this->assertContains($result, ['-05:00', '-04:00']); // EST/EDT
+
+        $result = $this->getPrivateMethodInvoker($db, 'convertTimezoneToOffset')('Europe/Paris');
+        $this->assertContains($result, ['+01:00', '+02:00']); // CET/CEST
+
+        $result = $this->getPrivateMethodInvoker($db, 'convertTimezoneToOffset')('Asia/Tokyo');
+        $this->assertSame('+09:00', $result); // JST (no DST)
+    }
+
+    public function testConvertTimezoneToOffsetWithInvalidTimezone(): void
+    {
+        $db = new MockConnection($this->options);
+
+        $result = $this->getPrivateMethodInvoker($db, 'convertTimezoneToOffset')('Invalid/Timezone');
+        $this->assertSame('+00:00', $result);
+    }
+
+    public function testGetSessionTimezoneWithFalse(): void
+    {
+        $options             = $this->options;
+        $options['timezone'] = false;
+        $db                  = new MockConnection($options);
+
+        $result = $this->getPrivateMethodInvoker($db, 'getSessionTimezone')();
+        $this->assertNull($result);
+    }
+
+    public function testGetSessionTimezoneWithTrue(): void
+    {
+        $options             = $this->options;
+        $options['timezone'] = true;
+        $db                  = new MockConnection($options);
+
+        $result = $this->getPrivateMethodInvoker($db, 'getSessionTimezone')();
+        $this->assertSame('+00:00', $result); // UTC = +00:00
+    }
+
+    public function testGetSessionTimezoneWithSpecificOffset(): void
+    {
+        $options             = $this->options;
+        $options['timezone'] = '+05:30';
+        $db                  = new MockConnection($options);
+
+        $result = $this->getPrivateMethodInvoker($db, 'getSessionTimezone')();
+        $this->assertSame('+05:30', $result);
+    }
+
+    public function testGetSessionTimezoneWithSpecificNamedTimezone(): void
+    {
+        $options             = $this->options;
+        $options['timezone'] = 'America/Chicago';
+        $db                  = new MockConnection($options);
+
+        $result = $this->getPrivateMethodInvoker($db, 'getSessionTimezone')();
+        $this->assertContains($result, ['-06:00', '-05:00']);
+    }
+
+    public function testGetSessionTimezoneWithoutTimezoneKey(): void
+    {
+        $db = new MockConnection($this->options);
+
+        $result = $this->getPrivateMethodInvoker($db, 'getSessionTimezone')();
+        $this->assertNull($result);
+    }
 }