varadhan

                static DateTime local_epoch = new DateTime (1970, 1, 1);

                public static int DateTimeToUnixtime_t (DateTime time)
                {
                        return ((int)time.Subtract (local_epoch).TotalSeconds);
                }

                [DllImport("glib-2.0")]
                static extern unsafe IntPtr g_slist_nth_data (IntPtr slist, int pos);

                [DllImport("glib-2.0")]
                static extern int g_slist_length (IntPtr slist);

                [DllImport("ecal")]
                static extern unsafe IntPtr e_cal_get_items_from_source (IntPtr source, int type, string query, out IntPtr e\rror);


                public static string[] GLibSListToStringArray (IntPtr slist)
                {
                        string[] ret;
                        int i = 0;
                        int len = 0;
                        IntPtr tmp = IntPtr.Zero;

                        len = g_slist_length (slist);
                        ret = new String [len];

                        for (i = 0; i < len; i++) {
                                tmp = g_slist_nth_data (slist, i);
                                ret[i] = GLib.Marshaller.PtrToStringGFree (tmp);
                        }
                        return ret;
                }

                public static string[] GetItemsFromSource (Evolution.Source source, Evolution.CalSourceType type, string que\ry) {
                        IntPtr error = IntPtr.Zero;

                        IntPtr raw_ret = e_cal_get_items_from_source (source.Handle, (int) type, query, out error);
                        if (error != IntPtr.Zero) throw new GLib.GException (error);
                        return GLibSListToStringArray (raw_ret);
                }

                [DllImport("ecal")]
                static extern unsafe IntPtr e_cal_get_items_from_source_occur_in_range (IntPtr source,
                                                                                        int type,
                                                                                        int start_date_time,
                                                                                        int end_date_time,
                                                                                        out IntPtr error);

                public static string[] GetItemsFromSourceOccurInRange (Evolution.Source source,
                                                                       Evolution.CalSourceType type,
                                                                       System.DateTime start_date_time,
                                                                       System.DateTime end_date_time) {
                        IntPtr error = IntPtr.Zero;
                        IntPtr raw_ret = e_cal_get_items_from_source_occur_in_range (source.Handle, (int) type,
                                                                                     DateTimeToUnixtime_t (start_date_time),
                                                                                     DateTimeToUnixtime_t (end_date_time),
                                                                                     out error);
                        if (error != IntPtr.Zero) throw new GLib.GException (error);
                        return GLibSListToStringArray (raw_ret);
                }