Localize dates and times

docs/configuration.rst

@@ -31,6 +31,7 @@ connection string. This will look like::
 
     SQLALCHEMY_DATABASE_URI = 'postgresql://myuser:mypass@localhost/dbname?client_encoding=utf8'
 
+.. _the SQLAlchemy documentation: http://docs.sqlalchemy.org/en/latest/core/engines.html#database-urls
 
 `SECRET_KEY`
 ------------
@@ -96,7 +97,26 @@ if set to ``"somestring"``, it will be served from a "folder"
 
 - **Default value:** ``""`` (empty string)
 
-.. _the SQLAlchemy documentation: http://docs.sqlalchemy.org/en/latest/core/engines.html#database-urls
+`BABEL_DEFAULT_TIMEZONE`
+------------------------
+
+The timezone that will be used to convert date and time when displaying them
+to the user (all times are always stored in UTC internally).
+If not set, it will default to the timezone configured on the Operating System
+of the server running ihatemoney, which may or may not be what you want.
+
+- **Default value:** *unset* (use the timezone of the server Operating System)
+- **Production value:** Set to the timezone of your expected users, with a
+  format such as ``"Europe/Paris"``. See `this list of TZ database names`_
+  for a complete list.
+
+Note: this setting is actually interpreted by Flask-Babel, see the
+`Flask-Babel guide for formatting dates`_ for details.
+
+.. _this list of TZ database name: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List
+
+.. _Flask-Babel guide for formatting dates: https://pythonhosted.org/Flask-Babel/#formatting-dates
+
 
 Configuring emails sending
 --------------------------

ihatemoney/conf-templates/ihatemoney.cfg.j2

@@ -34,3 +34,7 @@ ALLOW_PUBLIC_PROJECT_CREATION = True
 
 # If set to True, an administration dashboard is available.
 ACTIVATE_ADMIN_DASHBOARD = False
+
+# You can change the timezone used to display time.  By default it will be
+#derived from the server OS.
+#BABEL_DEFAULT_TIMEZONE = "Europe/Paris"

ihatemoney/history.py

@@ -82,7 +82,7 @@ def get_history(project, human_readable_names=True):
                 object_str = describe_version(version)
 
             common_properties = {
-                "time": version.transaction.issued_at.strftime("%Y-%m-%dT%H:%M:%SZ"),
+                "time": version.transaction.issued_at,
                 "operation_type": version.operation_type,
                 "object_type": object_type,
                 "object_desc": object_str,

ihatemoney/run.py

@@ -2,6 +2,7 @@
 import os.path
 import warnings
 
+from babel.dates import LOCALTZ
 from flask import Flask, g, render_template, request, session
 from flask_babel import Babel
 from flask_mail import Mail
@@ -146,8 +147,10 @@ def create_app(
     app.jinja_env.globals["locale_from_iso"] = locale_from_iso
     app.jinja_env.filters["minimal_round"] = minimal_round
 
-    # Translations
-    babel = Babel(app)
+    # Translations and time zone (used to display dates).  The timezone is
+    # taken from the BABEL_DEFAULT_TIMEZONE settings, and falls back to
+    # the local timezone of the server OS by using LOCALTZ.
+    babel = Babel(app, default_timezone=str(LOCALTZ))
 
     @babel.localeselector
     def get_locale():

ihatemoney/templates/history.html

@@ -177,7 +177,7 @@ <h3 class="modal-title">{{ _('Delete Confirmation') }}</h3>
     <tbody>
     {% for event in history %}
     <tr>
-            <td><script>document.write(localizeTime("{{ event.time }}"));</script></td>
+            <td>{{ event.time|datetimeformat("medium") }}</td>
             <td >
                 <div class="history_icon">
                     <i {% if event.operation_type == OperationType.INSERT  %}

ihatemoney/templates/list_bills.html

@@ -117,7 +117,7 @@ <h3 class="modal-title">{{ _('Add a bill') }}</h3>
         <tr owers="{{bill.owers|join(',','id')}}" payer="{{bill.payer.id}}">
                 <td>
                     <span data-toggle="tooltip" data-placement="top"
-                        title="{{ _('Added on %(date)s', date=bill.creation_date if bill.creation_date else bill.date) }}">
+                        title="{{ _('Added on %(date)s', date=bill.creation_date|dateformat("long") if bill.creation_date else bill.date|dateformat("long")) }}">
                         {{ bill.date }}
                     </span>
                 </td>