Bug: Table view groups events under wrong date when in BST (UTC+1)

[MrSimonC]

Summary

When in BST (British Summer Time, UTC+1), the ical list table view groups events under the wrong date. The times displayed are correctly converted to local time, but the date grouping/ordering appears to use UTC dates instead of local dates. This means events that occur in the late afternoon/evening BST can appear under the following day in the table output.

Reproduction Steps

1. Be in a BST timezone (Europe/London, during summer time, UTC+1)
2. Create a calendar event on a Sunday at 16:00 BST (e.g., Apr 19 2026 at 16:00 local)
3. Run:

   ical list --from "2026-04-19" --to "2026-04-21" --calendar "Shared"
   

4. Observe in the table output that the event appears grouped with Monday Apr 20 events instead of Sunday Apr 19

Expected Behavior

The event at 16:00 BST on Sunday Apr 19 should appear grouped under Sunday Apr 19 in the table view.

Actual Behavior

The event appears grouped under Monday Apr 20 in the table view.

Additional Context

• JSON output confirms the correct data: The JSON output (-o json) shows "start_date":"2026-04-19T15:00:00Z" which is correctly 16:00 BST on Apr 19. But the table view displays it under the wrong date.
• The time conversion itself is correct — 15:00Z is shown as 16:00 in the table. It's only the date grouping/row ordering that's wrong.

Suggested Fix

The date grouping logic in the table formatter likely uses the UTC date from start_date rather than converting to the local timezone first. The fix would be to convert the event's start time to the local timezone (or the event's timezone from the timezone field) before determining which date group to place it under.

Environment

• OS: macOS (Apple Silicon)
• ical version: v0.8.0
• Timezone: Europe/London (BST, UTC+1)

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Reported by @MrSimonC

[MrSimonC]

Hi — wanted to follow up with some findings after digging into the source code.

After reading through internal/ui/output.go and the dateparser/format.go in go-eventkit, I believe the timezone conversion itself is actually correct. localizeTime() properly converts event times to the system's local timezone (BST in my case) before display, FormatTimeRange() works with those localized times, and the sort in list.go uses StartDate.Before() which compares absolute instants — all behaving as expected.

The real issue turns out to be a UX/ergonomics problem with the table output when listing events across multiple days. Here's what happens:

• For same-day events, FormatTimeRange only shows times (e.g. "16:00 - 17:00") with no date indicator.
• The table has no date group headers or per-row date column.
• When you run something like ical list --from today --to "end of month", you get a long flat list where time-only rows are ambiguous about which date they belong to.
• You have to infer the date from context — multi-day events and all-day events do show dates, plus the sort order gives some clues, but it's easy to misread.

This is what led me to think events were appearing under the wrong day. A Sunday 16:00 BST event can look like it belongs to Monday's group because there's no visual date boundary between days.

Suggestion: When the listing spans more than one day, it would help a lot to either:

1. Add date group headers between days (e.g. ── Monday, Apr 20 ──), or
2. Add a date column to the table so every row is unambiguous.

Either approach would make multi-day listings much easier to scan. Happy to help with a PR if that would be useful!