How to build a chronology when some dates are only approximate

Record the precision of every date as a fact in its own right, alongside the date. An event known only to a month is placed at the earliest day it could have happened — the first of the month — for the purpose of ordering, and is printed as the month, never as a day it was not given. One known to lie between two dates is placed at the earlier of them. Then measure any gap between two events from the last day the earlier one could have happened to the first day the later one could, so that a vague date never manufactures a silence that the evidence does not support. Do that consistently and the chronology stays honest about what it knows, which is the whole of its value.

Why prose gets this wrong

“In March 2026 the tenant reported damp. On 14 March the agent acknowledged it. Around the 20th a contractor visited.” Read quickly, that is three dated events in order. Read carefully, the first is known to a month, the second to a day, and the third to within a few days of a day, and the sentence has quietly decided that the report came before the acknowledgement, which the evidence does not say: a report made on the 15th and an acknowledgement on the 14th are both consistent with it. A chronology's job is to stop that happening, and it can only do so if the precision is written down with the date rather than left in the wording.

Five kinds of date

The sorts from column is the ordering rule: the earliest day the event could have happened. Two events that could both begin on the same day are ordered with the one pinned to a single day first, because it is the more definite. The could be as late as column is what the gaps are measured from. And the prints as column is the discipline: an event known to a month must never appear on the page with a day attached, because the day would be believed.

A worked run

Six events from a deposit dispute, written the way a person writes them and pasted into CASEMAP as lines:

March 2026 — Tenant reports damp in the back bedroom by phone
14 March 2026 — Letting agent's email acknowledging the report
c. 20 March 2026 — Contractor visits, no report produced
between 1 and 14 April 2026 — Landlord says the contractor quoted
2026 — Tenant says damp was present from the start of the tenancy
2 June 2026 — Deposit deduction letter

It reads each line, says what precision it understood — month only, exact, approximately, between two dates, year only, exact — and adds nothing until you have checked the reading. Committed, the chronology comes out in this order: 2026, then March 2026, 14 March 2026, about 20 March 2026, between 1 April 2026 and 14 April 2026, 2 June 2026. The year-only claim sits at the top because 1 January is the earliest it could be true, and it prints as the bare year, which is exactly as much as anybody knows.

Then the quiet periods. With the threshold at thirty days the page reports one: 49 days, from 14 April to 2 June, between the landlord's quote and the deduction letter. It does not report one between the year-only claim and the March report, because the claim could be true as late as December, and it does not report one between the March report and the 14 March email, because the report could have been on the 31st. Measured from the last possible day of one event to the first possible day of the next, a gap is only ever a stretch the calendar genuinely has nothing in, which is the kind that tells you where the disclosure request should go. Raise the threshold to sixty days and there is none.

Every one of the six is also flagged nothing evidences this, because no document has been attached to any of them yet. That flag is the other half of the discipline: an event that points at a document is a fact, and one that does not is an assertion, and a chronology that makes them look the same has hidden the thing the reader most needs to know.

Writing dates so they can be read

• Say the precision in the date itself. March 2026, not early March unless you mean the first days; c., about, around or on or about for a day you are nearly sure of; between two dates, or 1–14 April 2026, for a range.
• Never let a system choose the day for you. A spreadsheet that turns March 2026 into 01/03/2026 has invented a fact, and it will be sorted on, filtered on and eventually quoted.
• Keep the source beside the date. A date on a document is known to the day; a date from memory is known to whatever the memory is good for, and the chronology should say which.
• Do not narrow a range to make it sort nicely. The earliest day is the ordering rule for every kind of date, so a range orders itself.

What CASEMAP does and does not do

CASEMAP holds a matter as people, documents, issues and events, with every event carrying its precision and pointing at the documents that prove it. It reads dates from pasted lines or a CSV, shows what it understood before adding anything, orders by the earliest possible day, prints only what the precision allows, reports the events nothing evidences, the documents nothing cites, and the quiet periods over a threshold you set, and produces the chronology as a document. Nothing is uploaded. It is checked on every build by applying the same rule to the six events above outside the tool and comparing the order, the printed dates and the one quiet period.

It does not know whether the memory a date came from is good, and it will not tell you what a quiet period means. It makes the precision and the evidence visible, which is what a chronology in prose is built to hide.