--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sat/tools/common/date_utils.py	Fri Jun 01 12:04:06 2018 +0200
@@ -0,0 +1,84 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+
+# SAT: a jabber client
+# Copyright (C) 2009-2018 Jérôme Poisson (goffi@goffi.org)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""tools to help manipulating time and dates"""
+
+from sat.core.constants import Const as C
+import datetime
+from babel import dates
+import time
+
+
+def date_fmt(timestamp, fmt='short', date_only=False, auto_limit=7, auto_old_fmt='short', auto_new_fmt='relative', locale_str=C.DEFAULT_LOCALE):
+    """format date according to locale
+
+    @param timestamp(basestring, int): unix time
+    @param fmt(str): one of:
+        - short: e.g. u'31/12/17'
+        - medium: e.g. u'Apr 1, 2007'
+        - long: e.g. u'April 1, 2007'
+        - full: e.g. u'Sunday, April 1, 2007'
+        - relative: format in relative time
+            e.g.: 3 hours
+            note that this format is not precise
+        - iso: ISO 8601 format
+            e.g.: u'2007-04-01T19:53:23Z'
+        - auto: use auto_old_fmt if date is older than auto_limit
+            else use auto_new_fmt
+        - auto_day: shorcut to set auto format with change on day
+            old format will be short, and new format will be time only
+        or a free value which is passed to babel.dates.format_datetime
+    @param date_only(bool): if True, only display date (not datetime)
+    @param auto_limit (int): limit in days before using auto_old_fmt
+        use 0 to have a limit at last midnight (day change)
+    @param auto_old_fmt(unicode): format to use when date is older than limit
+    @param auto_new_fmt(unicode): format to use when date is equal to or more recent
+        than limit
+
+    """
+    if fmt == 'auto_day':
+        fmt, auto_limit, auto_old_fmt, auto_new_fmt = 'auto', 0, 'short', 'HH:mm'
+    if fmt == 'auto':
+        if auto_limit == 0:
+            today = time.mktime(datetime.date.today().timetuple())
+            if int(timestamp) < today:
+                fmt = auto_old_fmt
+            else:
+                fmt = auto_new_fmt
+        else:
+            days_delta = (time.time() - int(timestamp)) / 3600
+            if days_delta > (auto_limit or 7):
+                fmt = auto_old_fmt
+            else:
+                fmt = auto_new_fmt
+
+    if fmt == 'relative':
+        delta = int(timestamp) - time.time()
+        return dates.format_timedelta(delta, granularity="minute", add_direction=True, locale=locale_str)
+    elif fmt in ('short', 'long'):
+        formatter = dates.format_date if date_only else dates.format_datetime
+        return formatter(int(timestamp), format=fmt, locale=locale_str)
+    elif fmt == 'iso':
+        if date_only:
+            fmt = 'yyyy-MM-dd'
+        else:
+            fmt = "yyyy-MM-ddTHH:mm:ss'Z'"
+        return dates.format_datetime(int(timestamp), format=fmt)
+    else:
+        return dates.format_datetime(int(timestamp), format=fmt, locale=locale_str)