Fix Google Calendar timezone handling

- Use event's TimeZone field when parsing DateTime
- Handle cases where DateTime has no timezone offset
- Parse in event timezone then convert to local for display

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 21 insertions, 3 deletions

diff --git a/internal/api/google_calendar.go b/internal/api/google_calendar.go
index dc61f3d..1b1971a 100644
--- a/internal/api/google_calendar.go
+++ b/internal/api/google_calendar.go
@@ -26,11 +26,29 @@ func parseEventTime(item *calendar.Event) (start, end time.Time) {
 		start, _ = time.ParseInLocation("2006-01-02", item.Start.Date, time.Local)
 		end, _ = time.ParseInLocation("2006-01-02", item.End.Date, time.Local)
 	} else {
-		// Timed event - parse RFC3339 then convert to local
+		// Timed event - use the event's timezone if specified
+		var loc *time.Location
+		if item.Start.TimeZone != "" {
+			loc, _ = time.LoadLocation(item.Start.TimeZone)
+		}
+		if loc == nil {
+			loc = time.Local
+		}
+
+		// Try parsing with timezone offset first (RFC3339)
 		start, _ = time.Parse(time.RFC3339, item.Start.DateTime)
 		end, _ = time.Parse(time.RFC3339, item.End.DateTime)
-		start = start.Local()
-		end = end.Local()
+
+		// If the parsed time is zero (parse failed) or missing timezone info,
+		// parse in the event's timezone
+		if start.IsZero() || item.Start.DateTime[len(item.Start.DateTime)-1] != 'Z' && !strings.Contains(item.Start.DateTime, "+") && !strings.Contains(item.Start.DateTime, "-") {
+			start, _ = time.ParseInLocation("2006-01-02T15:04:05", item.Start.DateTime, loc)
+			end, _ = time.ParseInLocation("2006-01-02T15:04:05", item.End.DateTime, loc)
+		}
+
+		// Convert to local timezone for display
+		start = start.In(time.Local)
+		end = end.In(time.Local)
 	}
 	return
 }