diff --git a/src/Type/DateTimeValue.php b/src/Type/DateTimeValue.php
index 763e201..a6b14e7 100644
--- a/src/Type/DateTimeValue.php
+++ b/src/Type/DateTimeValue.php
@@ -4,6 +4,7 @@
 
 namespace SimpleSAML\XML\Type;
 
+use DateTimeInterface;
 use SimpleSAML\XML\Assert\Assert;
 use SimpleSAML\XML\Exception\SchemaViolationException;
 
@@ -15,6 +16,9 @@
  */
 class DateTimeValue extends AbstractValueType
 {
+    public const string DATETIME_FORMAT = 'Y-m-d\\TH:i:sP';
+
+
     /**
      * Sanitize the value.
      *
@@ -38,4 +42,14 @@ protected function validateValue(string $value): void
     {
         Assert::validDateTime($this->sanitizeValue($value), SchemaViolationException::class);
     }
+
+
+    /**
+     * @param \DateTimeInterface $value
+     * @return static
+     */
+    public static function fromDateTime(DateTimeInterface $value): static
+    {
+        return new static($value->format(static::DATETIME_FORMAT));
+    }
 }
diff --git a/tests/Type/DateTimeValueTest.php b/tests/Type/DateTimeValueTest.php
index 47ded07..50fb068 100644
--- a/tests/Type/DateTimeValueTest.php
+++ b/tests/Type/DateTimeValueTest.php
@@ -4,6 +4,7 @@
 
 namespace SimpleSAML\Test\XML\Type;
 
+use DateTimeImmutable;
 use PHPUnit\Framework\Attributes\{CoversClass, DataProvider};
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\XML\Exception\SchemaViolationException;
@@ -57,4 +58,16 @@ public static function provideDateTime(): array
             'wrong format' => [false, '01-10-26T21:32'],
         ];
     }
+
+
+    /**
+     * Test the fromDateTime function
+     */
+    public function testFromDateTime(): void
+    {
+        $dt = new DateTimeImmutable('@946684800');
+
+        $dateTimeValue = DateTimeValue::fromDateTime($dt);
+        $this->assertEquals('2000-01-01T00:00:00+00:00', $dateTimeValue->getValue());
+    }
 }