Series: moving a session moves the ones after it, keeping the pattern (#730 L6) #804

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opened 2026-09-24 05:22:07 +00:00 by claude-bot · 0 comments

claude-bot commented

2026-09-24 05:22:07 +00:00

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Owner, 2026-09-24 (lane 4 survey, #730 L6). The owner rescheduled a session in their own recurring game, and it now falls after the series' next session. "If I reschedule a session, it will automatically move the following sessions … (doesn't shift the pattern)."

Today

materialize_session_series (app/tasks/reminder_tasks.py ~7182) creates every occurrence up to 28 days ahead (SERIES_MATERIALIZE_WINDOW_DAYS), all as confirmed, keyed uniquely on (series_id, series_occurrence_date). Rescheduling one session (session_service reschedule, ~458) moves only that session, so it can land on or past its successors.

The rule

When a series session is moved, walk the series' later sessions in date order:

Each one must sit on a regular day of the series that is at least half an interval after the session before it.
If a session already satisfies that, stop. Everything after it is untouched.
Otherwise, move it to the first regular day that does. The pattern's days never change, only which session sits on which slot.

Example, every other Monday, with sessions on 5 Oct, 19 Oct and 2 Nov:

Move 5 Oct to Thursday 8 Oct. Nothing else moves, because 19 Oct is 11 days later, which is more than half of 14.
Move 5 Oct to Thursday 22 Oct instead. 19 Oct goes to 2 Nov, and 2 Nov goes to 16 Nov.

A session that moves under this rule:

has its answers re-asked, like any move (L6);
tells its people, with the usual notice;
keeps its identity: its number (D86), notes and title.

Where the walk stops without moving anything. Every series session is created confirmed, so "confirmed" marks nothing special. What does mark something is a session the GM has already moved by hand: its time no longer matches its occurrence slot. The walk also stops at a session detached from the series, or one that is cancelled or played. The walk never rearranges a session somebody deliberately placed. If the ripple would need to move past such a session, stop, and say so on the move form, so the GM can move it too. This is the conservative reading; confirm it with the owner when it's built.

What it needs

The vacated slot must not be refilled. The materialiser's rolling window would recreate 19 Oct an hour later. The series needs a record of occurrence dates that are skipped or taken, or the materialiser must skip any occurrence date earlier than a session that already occupies a later slot. Choose the simpler of the two, and test it against the hourly run.
The GM's move form says what else will move before they save, for example: "Two later sessions move with it: 19 Oct → 2 Nov, 2 Nov → 16 Nov." Nothing moves silently.
Tests at the service level:
- the walk and its stop;
- a move that needs no ripple;
- a move into the half-interval gap;
- the materialiser not refilling the vacated slot;
- a hand-moved, detached, cancelled or played session stopping the walk.

Built in lane 4's scheduling server PR (#730), alongside L6's re-ask and L7's pencilled-in → vote.

🤖 Generated with Claude Code

**Owner, 2026-09-24 (lane 4 survey, #730 L6).** The owner rescheduled a session in their own recurring game, and it now falls *after* the series' next session. "If I reschedule a session, it will automatically move the following sessions … (doesn't shift the pattern)." ## Today `materialize_session_series` (`app/tasks/reminder_tasks.py` ~7182) creates every occurrence up to 28 days ahead (`SERIES_MATERIALIZE_WINDOW_DAYS`), all as `confirmed`, keyed uniquely on `(series_id, series_occurrence_date)`. Rescheduling one session (`session_service` reschedule, ~458) moves only that session, so it can land on or past its successors. ## The rule When a series session is moved, walk the series' later sessions in date order: - Each one must sit on a **regular day of the series** that is **at least half an interval after** the session before it. - If a session already satisfies that, stop. Everything after it is untouched. - Otherwise, move it to the first regular day that does. The pattern's days never change, only which session sits on which slot. Example, every other Monday, with sessions on 5 Oct, 19 Oct and 2 Nov: - Move 5 Oct to Thursday 8 Oct. Nothing else moves, because 19 Oct is 11 days later, which is more than half of 14. - Move 5 Oct to Thursday 22 Oct instead. 19 Oct goes to 2 Nov, and 2 Nov goes to 16 Nov. A session that moves under this rule: - has its answers **re-asked**, like any move (L6); - tells its people, with the usual notice; - **keeps its identity**: its number (D86), notes and title. **Where the walk stops without moving anything.** Every series session is created `confirmed`, so "confirmed" marks nothing special. What does mark something is a session the GM has **already moved by hand**: its time no longer matches its occurrence slot. The walk also stops at a session **detached from the series**, or one that is **cancelled or played**. The walk never rearranges a session somebody deliberately placed. If the ripple would need to move past such a session, stop, and say so on the move form, so the GM can move it too. This is the conservative reading; confirm it with the owner when it's built. ## What it needs - **The vacated slot must not be refilled.** The materialiser's rolling window would recreate 19 Oct an hour later. The series needs a record of occurrence dates that are skipped or taken, or the materialiser must skip any occurrence date earlier than a session that already occupies a later slot. Choose the simpler of the two, and test it against the hourly run. - The GM's move form says what else will move before they save, for example: "Two later sessions move with it: 19 Oct → 2 Nov, 2 Nov → 16 Nov." Nothing moves silently. - Tests at the service level: - the walk and its stop; - a move that needs no ripple; - a move into the half-interval gap; - the materialiser not refilling the vacated slot; - a hand-moved, detached, cancelled or played session stopping the walk. Built in lane 4's scheduling server PR (#730), alongside L6's re-ask and L7's pencilled-in → vote. 🤖 Generated with [Claude Code](https://claude.com/claude-code)

claude-bot referenced this issue

2026-09-24 05:22:33 +00:00

Build lane 4: sessions (SESS-1 to SESS-7) #730