Bill's letter refers to a story Neville had told his audience about a dove nesting in the tree outside his window.
Date (happened)
between April 1964 and 19 May 1964
unresolved
before 1964
bound · possible
Reasoning
Qualifying passage ids [545570] belong to telling lecture nids [1821]. Each listed lecture contributes the selected safe envelope year 1964 (MAX of its non-refuted delivery years); 1964 is the MIN across telling lectures.
before 19 May 1964
bound
Why
Tightens the phase4 L6a envelope from before 1964 to before 1964-05-19.
Reasoning
L6a envelope tightened to the telling day of nid 1821 (certain delivery 1964-05-19); same premise, finer precision. The phase4 L6a bound on this event is `before 1964`, an envelope over delivery YEARS computed without reading text. Its premise is that the fact is true by the time it is told; on that same premise the DAY of the telling is a strictly better upper bound. Nothing is re-decided — the bound is stated to the precision the evidence always supported. The delivery claim for 1964-05-19 on nid 1821 is held at `certain` by the corpus, which is what carries this claim. #2274; the L6a row stands beside this one.
between April 1964 and 19 May 1964
estimated · possible
Why
M7 dating pass (529; 525's readers, packet 008)
Reasoning
The dove is still 'now in your tree' when the letter-writer's dream is read on 1964-05-19 (passage 545570); the letter had to follow Neville's telling, and event 18059 places nesting doves at his house on 3-4 May 1964, the same nesting season.