From f4672564ceaad5576087c3ef3b74156ddc12a5c7 Mon Sep 17 00:00:00 2001
From: Raphael Michel <mail@raphaelmichel.de>
Date: Sun, 25 Dec 2016 22:51:19 +0100
Subject: [PATCH] Fix #37 -- Clever displaying of date ranges

---
 src/pretix/base/models/event.py               |  7 +++++++
 src/pretix/helpers/daterange.py               | 21 +++++++++++++++++++
 .../templates/pretixpresale/event/base.html   |  3 +--
 3 files changed, 29 insertions(+), 2 deletions(-)
 create mode 100644 src/pretix/helpers/daterange.py

diff --git a/src/pretix/base/models/event.py b/src/pretix/base/models/event.py
index 122df60e1..8ac9c2bb3 100644
--- a/src/pretix/base/models/event.py
+++ b/src/pretix/base/models/event.py
@@ -17,6 +17,7 @@ from pretix.base.i18n import I18nCharField
 from pretix.base.models.base import LoggedModel
 from pretix.base.settings import SettingsProxy
 from pretix.base.validators import EventSlugBlacklistValidator
+from pretix.helpers.daterange import daterange
 
 from .auth import User
 from .organizer import Organizer
@@ -153,6 +154,12 @@ class Event(LoggedModel):
             "DATETIME_FORMAT" if self.settings.show_times else "DATE_FORMAT"
         )
 
+    def get_date_range_display(self, tz=None) -> str:
+        tz = tz or pytz.timezone(self.settings.timezone)
+        if not self.settings.show_date_to or not self.date_to:
+            return _date(self.date_from.astimezone(tz), "DATE_FORMAT")
+        return daterange(self.date_from.astimezone(tz), self.date_to.astimezone(tz))
+
     def get_cache(self) -> "pretix.base.cache.ObjectRelatedCache":
         """
         Returns an :py:class:`ObjectRelatedCache` object. This behaves equivalent to
diff --git a/src/pretix/helpers/daterange.py b/src/pretix/helpers/daterange.py
new file mode 100644
index 000000000..65f86e08c
--- /dev/null
+++ b/src/pretix/helpers/daterange.py
@@ -0,0 +1,21 @@
+from django.template.defaultfilters import date as _date
+from django.utils.translation import get_language, ugettext_lazy as _
+
+
+def daterange(df, dt):
+    lng = get_language()
+
+    if lng.startswith("de"):
+        if df.year == dt.year and df.month == dt.month:
+            return "{}.–{}".format(_date(df, "j"), _date(dt, "j. F Y"))
+        elif df.year == dt.year:
+            return "{} – {}".format(_date(df, "j. F"), _date(dt, "j. F Y"))
+    elif lng.startswith("en"):
+        if df.year == dt.year and df.month == dt.month:
+            return "{} – {}".format(_date(df, "N jS"), _date(dt, "jS, Y"))
+        elif df.year == dt.year:
+            return "{} – {}".format(_date(df, "N jS"), _date(dt, "N jS, Y"))
+
+    return _("{date_from} – {date_to}").format(
+        date_from=_date(df, "DATE_FORMAT"), date_to=_date(dt, "DATE_FORMAT")
+    )
diff --git a/src/pretix/presale/templates/pretixpresale/event/base.html b/src/pretix/presale/templates/pretixpresale/event/base.html
index 90a148599..c53cfb82b 100644
--- a/src/pretix/presale/templates/pretixpresale/event/base.html
+++ b/src/pretix/presale/templates/pretixpresale/event/base.html
@@ -29,8 +29,7 @@
                 </a>
             {% else %}
                 <a href="{% eventurl event "presale:event.index" %}">{{ event.name }}</a>
-                <small>{{ event.date_from|date:"DATE_FORMAT" }}{% if event.settings.show_date_to %} –
-                    {{ event.date_to|date:"DATE_FORMAT" }}{% endif %}</small>
+                <small>{{ event.get_date_range_display }}</small>
             {% endif %}
         </h1>
         <div class="pull-right loginbox">