# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1423341200 -3600
# Node ID 5291a33d8fc7e7afb561a44c928f5877e2072ce1
# Parent  bca36db624cea5b4b918dd81c413a46feb8cc005
Prevent bad datetimes from being interpreted as dates.
Added time formatting and datetime-to-date functions.

diff -r bca36db624ce -r 5291a33d8fc7 imiptools/dates.py
--- a/imiptools/dates.py	Sat Feb 07 18:33:40 2015 +0100
+++ b/imiptools/dates.py	Sat Feb 07 21:33:20 2015 +0100
@@ -85,6 +85,20 @@
     else:
         return dt.strftime("%Y%m%d")
 
+def format_time(dt):
+
+    "Format the time portion of 'dt' as an iCalendar-compatible string."
+
+    if not dt:
+        return None
+    elif isinstance(dt, datetime):
+        if dt.tzname() == "UTC":
+            return dt.strftime("%H%M%SZ")
+        else:
+            return dt.strftime("%H%M%S")
+    else:
+        return None
+
 def get_datetime_item(dt, tzid):
 
     "Return an iCalendar-compatible string and attributes for 'dt' and 'tzid'."
@@ -102,7 +116,7 @@
     the 'attr' mapping (if specified) to control the conversion.
     """
 
-    if not attr or attr.get("VALUE") in (None, "DATE-TIME"):
+    if len(value) > 9 and (not attr or attr.get("VALUE") in (None, "DATE-TIME")):
         m = match_datetime_icalendar(value)
         if m:
             year, month, day, hour, minute, second = map(m.group, [
@@ -119,6 +133,8 @@
 
                 return to_timezone(dt, m.group("utc") and "UTC" or attr and attr.get("TZID") or None)
 
+        return None
+
     # Permit dates even if the VALUE is not set to DATE.
 
     if not attr or attr.get("VALUE") in (None, "DATE"):
@@ -129,6 +145,12 @@
 
     return None
 
+def get_date(dt):
+
+    "Return the date of 'dt'."
+
+    return date(dt.year, dt.month, dt.day)
+
 def get_start_of_day(dt, tzid):
 
     """