# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1444149525 -7200
# Node ID 058e27a598ae02bbeac389e1e482de6de8376189
# Parent  eb49f6382f80419d5b5b08a80a0fb16e3d33ec02
Supported setting the main period via set_periods.

diff -r eb49f6382f80 -r 058e27a598ae imiptools/data.py
--- a/imiptools/data.py	Tue Oct 06 00:09:07 2015 +0200
+++ b/imiptools/data.py	Tue Oct 06 18:38:45 2015 +0200
@@ -411,14 +411,18 @@
         if self.has_key("RDATE"):
             del self["RDATE"]
 
+        main_changed = False
+
         for p in periods:
-            if p.origin != "RRULE":
+            if p.origin == "RDATE":
                 new_rdates.append(get_period_item(p.get_start(), p.get_end()))
+            elif p.origin == "DTSTART":
+                main_changed = self.set_period(p)
 
         if new_rdates:
             self["RDATE"] = new_rdates
 
-        return old_values != set(self.get_date_values("RDATE") or [])
+        return main_changed or old_values != set(self.get_date_values("RDATE") or [])
 
     def update_dtstamp(self):