diff --git a/requirements.txt b/requirements.txt
index 5bd19d3..d2416de 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,2 @@
 flask==3.0.0
+pytz==2023.3.post1
diff --git a/src/routes/set_timezone.py b/src/routes/set_timezone.py
new file mode 100644
index 0000000..f073e66
--- /dev/null
+++ b/src/routes/set_timezone.py
@@ -0,0 +1,15 @@
+from flask import Blueprint, jsonify, request, session
+from utils.config import Config
+from werkzeug import Response
+
+name = __name__.split(".")[-1]
+router = Blueprint(name, __name__)
+
+
+@router.route(f"/{name}", methods=["POST"])
+def set_timezone() -> Response:
+    """set timezone"""
+    timezone = request.data.decode("utf-8")
+    session[Config._session_timezone] = timezone
+
+    return jsonify(success=True)
diff --git a/src/templates/index.html b/src/templates/index.html
index 3445eb2..b6c1bd6 100644
--- a/src/templates/index.html
+++ b/src/templates/index.html
@@ -23,5 +23,7 @@
       </ul>
       {% endif %}
     </main>
+
+    {% include "tz.html" %}
   </body>
 </html>
diff --git a/src/templates/login.html b/src/templates/login.html
index fedb215..b15bb54 100644
--- a/src/templates/login.html
+++ b/src/templates/login.html
@@ -22,5 +22,7 @@
         </form></span
       >
     </main>
+
+    {% include "tz.html" %}
   </body>
 </html>
diff --git a/src/templates/read.html b/src/templates/read.html
index 0451a1d..3f496aa 100644
--- a/src/templates/read.html
+++ b/src/templates/read.html
@@ -23,5 +23,7 @@
         <a href="/">back to index</a>
       </p>
     </footer>
+
+    {% include "tz.html" %}
   </body>
 </html>
diff --git a/src/templates/tz.html b/src/templates/tz.html
new file mode 100644
index 0000000..4e0b184
--- /dev/null
+++ b/src/templates/tz.html
@@ -0,0 +1,6 @@
+{% if "timezone" not in session %}
+<script type="text/javascript">
+  const timezone = Intl.DateTimeFormat().resolvedOptions().timeZone;
+  fetch("/set_timezone", { method: "POST", body: timezone });
+</script>
+{% endif %}
diff --git a/src/utils/config.py b/src/utils/config.py
index 733e3c0..abac5f8 100644
--- a/src/utils/config.py
+++ b/src/utils/config.py
@@ -32,6 +32,9 @@ class Config:
     # where is stored the password info
     _session_login = "logged_in"
 
+    # where is stored the timezone info
+    _session_timezone = "timezone"
+
     # data location
     data_dir = "data"
 
diff --git a/src/utils/misc.py b/src/utils/misc.py
index e6af1a9..a38db4c 100644
--- a/src/utils/misc.py
+++ b/src/utils/misc.py
@@ -1,8 +1,11 @@
+from datetime import datetime
 from os import listdir, utime
 from os import path as os_path
 from os import remove as os_remove
 from time import ctime
 
+from flask import session
+from pytz import timezone
 from utils.config import Config
 
 
@@ -80,6 +83,11 @@ def exist_post(file_id: int) -> float | None:
         return None
 
 
+def time_now() -> float:
+    """get current time with timezone awareness"""
+    return datetime.now(timezone(session[Config._session_timezone])).timestamp()
+
+
 def create_post(file_id: int, content: str) -> bool:
     """create a post"""
     # check if the file already exists
@@ -91,8 +99,12 @@ def create_post(file_id: int, content: str) -> bool:
     with open(filename, "w", encoding="utf-8") as f:
         f.write(content)
 
-    # keep metadata
     if update:
+        # keep metadata
         utime(filename, (update, update))
         return True
-    return False
+    else:
+        # use user's tz
+        now = time_now()
+        utime(filename, (now, now))
+        return False