diff -r 044dc196ec8a -r d3668ecd9137 src/ztfy/utils/date.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/ztfy/utils/date.py	Wed Jun 20 16:29:53 2012 +0200
@@ -0,0 +1,133 @@
+### -*- coding: utf-8 -*- ####################################################
+##############################################################################
+#
+# Copyright (c) 2008 Thierry Florac <tflorac AT ulthar.net>
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+
+
+# import standard packages
+from datetime import datetime
+
+# import Zope3 interfaces
+
+# import local interfaces
+
+# import Zope3 packages
+from zope.datetime import parseDatetimetz
+from zope.i18n import translate
+
+# import local packages
+from timezone import gmtime
+
+from ztfy.utils import _
+
+
+def unidate(value):
+    """Get specified date converted to unicode ISO format
+    
+    Dates are always assumed to be stored in GMT timezone
+    
+    @param value: input date to convert to unicode
+    @type value: date or datetime
+    @return: input date converted to unicode
+    @rtype: unicode
+    """
+    if value is not None:
+        value = gmtime(value)
+        return unicode(value.isoformat('T'), 'ascii')
+    return None
+
+
+def parsedate(value):
+    """Get date specified in unicode ISO format to Python datetime object
+    
+    Dates are always assumed to be stored in GMT timezone
+    
+    @param value: unicode date to be parsed
+    @type value: unicode
+    @return: the specified value, converted to datetime
+    @rtype: datetime
+    """
+    if value is not None:
+        return gmtime(parseDatetimetz(value))
+    return None
+
+
+def datetodatetime(value):
+    """Get datetime value converted from a date or datetime object
+    
+    @param value: a date or datetime value to convert
+    @type value: date or datetime
+    @return: input value converted to datetime
+    @rtype: datetime
+    """
+    if type(value) is datetime:
+        return value
+    return datetime(value.year, value.month, value.day)
+
+
+def getAge(value):
+    """Get age of a given datetime (including timezone) compared to current datetime (in UTC)
+    
+    @param value: a datetime value, including timezone
+    @type value: datetime
+    @return: string representing value age
+    @rtype: gettext translated string
+    """
+    now = gmtime(datetime.utcnow())
+    delta = now - value
+    if delta.days > 60:
+        return translate(_("%d months ago")) % int(round(delta.days * 1.0 / 30))
+    elif delta.days > 10:
+        return translate(_("%d weeks ago")) % int(round(delta.days * 1.0 / 7))
+    elif delta.days > 2:
+        return translate(_("%d days ago")) % delta.days
+    elif delta.days == 2:
+        return translate(_("the day before yesterday"))
+    elif delta.days == 1:
+        return translate(_("yesterday"))
+    else:
+        hours = int(round(delta.seconds * 1.0 / 3600))
+        if hours > 1:
+            return translate(_("%d hours ago")) % hours
+        elif delta.seconds > 300:
+            return translate(_("%d minutes ago")) % int(round(delta.seconds * 1.0 / 60))
+        else:
+            return translate(_("less than 5 minutes ago"))
+
+
+def getDuration(v1, v2=None):
+    """Get delta between two dates"""
+    if v2 is None:
+        v2 = datetime.utcnow()
+    assert isinstance(v1, datetime) and isinstance(v2, datetime)
+    v1, v2 = min(v1, v2), max(v1, v2)
+    delta = v2 - v1
+    if delta.days > 60:
+        return translate(_("%d months")) % int(round(delta.days * 1.0 / 30))
+    elif delta.days > 10:
+        return translate(_("%d weeks")) % int(round(delta.days * 1.0 / 7))
+    elif delta.days >= 2:
+        return translate(_("%d days")) % delta.days
+    else:
+        hours = int(round(delta.seconds * 1.0 / 3600))
+        if delta.days == 1:
+            return translate(_("%d day and %d hours")) % (delta.days, hours)
+        else:
+            if hours > 2:
+                return translate(_("%d hours")) % hours
+            else:
+                minutes = int(round(delta.seconds * 1.0 / 60))
+                if minutes > 2:
+                    return translate(_("%d minutes")) % minutes
+                else:
+                    return translate(_("%d seconds")) % delta.seconds