diff --git a/de.srsoftware.oidc.api/src/main/java/de/srsoftware/oidc/api/SessionService.java b/de.srsoftware.oidc.api/src/main/java/de/srsoftware/oidc/api/SessionService.java
index 65c7034..0667030 100644
--- a/de.srsoftware.oidc.api/src/main/java/de/srsoftware/oidc/api/SessionService.java
+++ b/de.srsoftware.oidc.api/src/main/java/de/srsoftware/oidc/api/SessionService.java
@@ -3,7 +3,6 @@ package de.srsoftware.oidc.api;
 
 import de.srsoftware.oidc.api.data.Session;
 import de.srsoftware.oidc.api.data.User;
-import java.time.Duration;
 import java.util.Optional;
 
 public interface SessionService {
@@ -11,5 +10,4 @@ public interface SessionService {
 	SessionService	  dropSession(String sessionId);
 	Session	  extend(Session session, User user);
 	Optional<Session> retrieve(String sessionId);
-	SessionService	  setDuration(Duration duration);
 }
diff --git a/de.srsoftware.oidc.datastore.file/src/main/java/de/srsoftware/oidc/datastore/file/FileStore.java b/de.srsoftware.oidc.datastore.file/src/main/java/de/srsoftware/oidc/datastore/file/FileStore.java
index ecb513b..e3d9ba0 100644
--- a/de.srsoftware.oidc.datastore.file/src/main/java/de/srsoftware/oidc/datastore/file/FileStore.java
+++ b/de.srsoftware.oidc.datastore.file/src/main/java/de/srsoftware/oidc/datastore/file/FileStore.java
@@ -5,6 +5,7 @@ import static de.srsoftware.oidc.api.data.User.*;
 import static de.srsoftware.utils.Optionals.nullable;
 import static de.srsoftware.utils.Strings.uuid;
 import static java.lang.System.Logger.Level.*;
+import static java.time.temporal.ChronoUnit.SECONDS;
 import static java.util.Optional.empty;
 
 import de.srsoftware.oidc.api.*;
@@ -17,7 +18,6 @@ import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.time.Duration;
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
 import java.util.*;
@@ -221,7 +221,7 @@ public class FileStore implements AuthorizationService, ClientService, SessionSe
 	@Override
 	public Session createSession(User user) {
 		var now	 = Instant.now();
-		var endOfSession = now.plus(user.sessionDuration());
+		var endOfSession = now.plus(user.sessionDuration()).truncatedTo(SECONDS);
 		return save(new Session(user.uuid(), endOfSession, uuid()));
 	}
 
@@ -247,7 +247,7 @@ public class FileStore implements AuthorizationService, ClientService, SessionSe
 		try {
 			var session    = sessions().getJSONObject(sessionId);
 			var userId     = session.getString(USER);
-			var expiration = Instant.ofEpochSecond(session.getLong(EXPIRATION));
+			var expiration = Instant.ofEpochSecond(session.getLong(EXPIRATION)).truncatedTo(SECONDS);
 			if (expiration.isAfter(Instant.now())) return Optional.of(new Session(userId, expiration, sessionId));
 			dropSession(sessionId);
 		} catch (Exception ignored) {
@@ -261,11 +261,6 @@ public class FileStore implements AuthorizationService, ClientService, SessionSe
 		return session;
 	}
 
-	@Override
-	public SessionService setDuration(Duration duration) {
-		return null;
-	}
-
 	/** client service methods **/
 
 	@Override
diff --git a/de.srsoftware.oidc.datastore.file/src/test/java/de/srsoftware/oidc/datastore/file/SessionServiceTest.java b/de.srsoftware.oidc.datastore.file/src/test/java/de/srsoftware/oidc/datastore/file/SessionServiceTest.java
index 9ec6fd6..7c814c7 100644
--- a/de.srsoftware.oidc.datastore.file/src/test/java/de/srsoftware/oidc/datastore/file/SessionServiceTest.java
+++ b/de.srsoftware.oidc.datastore.file/src/test/java/de/srsoftware/oidc/datastore/file/SessionServiceTest.java
@@ -2,6 +2,7 @@
 package de.srsoftware.oidc.datastore.file;
 
 import static de.srsoftware.utils.Strings.uuid;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import de.srsoftware.oidc.api.SessionService;
@@ -45,7 +46,7 @@ public class SessionServiceTest {
 	}
 
 	@Test
-	public void testCreate() {
+	public void testCreateAndLoad() {
 		var uuid = uuid();
 		var pass = hasher().hash(PASSWORD, uuid);
 		var user = new User(USERNAME, pass, REALNAME, EMAIL, uuid).sessionDuration(Duration.ofMinutes(5));
@@ -55,5 +56,55 @@ public class SessionServiceTest {
 		var     expiration = session.expiration();
 		assertTrue(expiration.isAfter(now.plus(5, ChronoUnit.MINUTES).minusSeconds(1)));
 		assertTrue(expiration.isBefore(now.plus(5, ChronoUnit.MINUTES).plusSeconds(1)));
+
+		var loaded = sessionService.retrieve(session.id());
+		assertTrue(loaded.isPresent());
+		assertEquals(session, loaded.get());
+	}
+
+	@Test
+	public void testCreateAndExtend() {
+		var uuid = uuid();
+		var pass = hasher().hash(PASSWORD, uuid);
+		var user = new User(USERNAME, pass, REALNAME, EMAIL, uuid).sessionDuration(Duration.ofMinutes(5));
+
+		var session = sessionService.createSession(user);
+
+		Instant now = Instant.now();
+		sessionService.extend(session, user.sessionDuration(Duration.ofMinutes(10)));
+		var loaded = sessionService.retrieve(session.id());
+		assertTrue(loaded.isPresent());
+		assertEquals(session.id(), loaded.get().id());
+		var expiration = loaded.get().expiration();
+		assertTrue(expiration.isAfter(now.plus(10, ChronoUnit.MINUTES).minusSeconds(1)));
+		assertTrue(expiration.isBefore(now.plus(10, ChronoUnit.MINUTES).plusSeconds(1)));
+	}
+
+	@Test
+	public void textCreateAndDrop() {
+		var uuid = uuid();
+		var pass = hasher().hash(PASSWORD, uuid);
+		var user = new User(USERNAME, pass, REALNAME, EMAIL, uuid).sessionDuration(Duration.ofMinutes(5));
+
+		var session = sessionService.createSession(user);
+		assertTrue(sessionService.retrieve(session.id()).isPresent());
+
+		sessionService.dropSession(session.id());
+		var loaded = sessionService.retrieve(session.id());
+		assertTrue(sessionService.retrieve(session.id()).isEmpty());
+	}
+
+	@Test
+	public void testExpiration() throws InterruptedException {
+		var uuid = uuid();
+		var pass = hasher().hash(PASSWORD, uuid);
+		var user = new User(USERNAME, pass, REALNAME, EMAIL, uuid).sessionDuration(Duration.ofSeconds(2));
+
+		var session = sessionService.createSession(user);
+		assertTrue(sessionService.retrieve(session.id()).isPresent());
+
+		Thread.sleep(2500);
+
+		assertTrue(sessionService.retrieve(session.id()).isEmpty());
 	}
 }
diff --git a/de.srsoftware.oidc.datastore.sqlite/src/main/java/de/srsoftware/oidc/datastore/sqlite/SqliteSessionService.java b/de.srsoftware.oidc.datastore.sqlite/src/main/java/de/srsoftware/oidc/datastore/sqlite/SqliteSessionService.java
index 46bcf8d..58921f7 100644
--- a/de.srsoftware.oidc.datastore.sqlite/src/main/java/de/srsoftware/oidc/datastore/sqlite/SqliteSessionService.java
+++ b/de.srsoftware.oidc.datastore.sqlite/src/main/java/de/srsoftware/oidc/datastore/sqlite/SqliteSessionService.java
@@ -5,7 +5,6 @@ import de.srsoftware.oidc.api.SessionService;
 import de.srsoftware.oidc.api.data.Session;
 import de.srsoftware.oidc.api.data.User;
 import java.sql.Connection;
-import java.time.Duration;
 import java.util.Optional;
 
 public class SqliteSessionService implements SessionService {
@@ -31,9 +30,4 @@ public class SqliteSessionService implements SessionService {
 	public Optional<Session> retrieve(String sessionId) {
 		return Optional.empty();
 	}
-
-	@Override
-	public SessionService setDuration(Duration duration) {
-		return null;
-	}
 }