ICAL.Time.fromJSDate(window, false) interpreted the UTC-midnight window bounds in the server's local TZ (America/New_York in dev), shifting the window by the server offset and dropping evening occurrences near a day window's end (e.g. June 11 17:45-04:00 = 21:45Z was excluded from the June-11 day view). Use UTC so the window is deterministic and correct.