1 files changed, 38 insertions, 0 deletions
diff --git a/src/Timestamp.php b/src/Timestamp.php
new file mode 100644
index 0000000..a23ba13
--- /dev/null
+++ b/src/Timestamp.php
@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Zhineng\Snowflake;
+
+final class Timestamp extends Field
+{
+    use Makable;
+
+    /**
+     * The epoch in milliseconds.
+     */
+    public readonly int $epoch;
+
+    public function __construct(
+        string $name = 'timestamp',
+        int $bits = 41,
+        \DateTime|int|null $epoch = null
+    ) {
+        parent::__construct($name, $bits);
+
+        $this->epoch = $epoch instanceof \DateTime
+            ? $epoch->getTimestamp() * 1000
+            : ($epoch ?? 0);
+
+        if ($this->epoch < 0) {
+            throw new \InvalidArgumentException('Epoch must be non-negative.');
+        }
+    }
+
+    public function value(): int
+    {
+        $now = (int) floor(microtime(as_float: true) * 1000);
+
+        return $now - $this->epoch;
+    }
+}