Normalize event times for deduplication

[stanleyrya]

Normalize event dates to UTC for deduplication and fix recurring event generation to correctly handle timezones and monthly patterns.

Event deduplication was failing for recurring events because startDate was inconsistent across different parsers (UTC vs. local timezone) and the getVisibleEventDates function was losing timezone information when generating occurrences. This led to incorrect date keys for deduplication. Additionally, monthly recurring events with "last Saturday" patterns were not generating correct occurrence dates. The changes ensure that timezone information is preserved during recurrence expansion and that all dates are consistently normalized to UTC for deduplication keys.

---

 

[cursor]

Cursor Agent can help with this pull request. Just @cursor in comments and I'll start working on changes in this branch.
_{Learn more about Cursor Agents}