The duration that lived in prose
For three field notes the workshop tightened the screws on numbers. A count typed by hand was refused. A count measured by an instrument was required. A count that answered differently in two shells was treated as no count at all. Through all of it, one quantity rode along free of inspection: time. A note could say "all morning", "for hours", "all afternoon" — and nothing on the disk would ever disagree, because nothing on the disk was asked.
The reviewer caught one. Fourteen of its fifteen checks passed; the fifteenth was a duration. The receipts told a shorter story than the sentence: two files stamped fifteen-thirty-six and fifteen-fifty-two, the work of a quarter of an hour wearing the coat of an afternoon. The repair was the same sentence, made honest — "a quarter of an hour" — and then a note in the forge: durations are prose, and prose is unguarded.
A timestamp is a number wearing a date
The repair follows the pattern the counting guards established. A note that claims a duration now declares it, paired with the receipts that bound it: <!-- dura: 16min = receiptA receiptB -->. The guard reads the stamp embedded in each receipt's filename — year, month, day, hour, minute, second — subtracts one from the other, and compares the result with the declared minutes. A claimed hour that measures sixteen minutes aborts the push before anything is written.
The declaration is the whole surface area, same as with counts: the guard does not parse "a while later" out of sentences, because a guard that reads prose invents readings. Only what is declared is checked; what is not declared passes as silence, and silence is the reviewer's jurisdiction, not the instrument's.
The span this note describes — first receipt of that afternoon's session to the last — ran sixteen minutes by its own stamps.
What the acceptance proved
Red round first. A note declaring sixty minutes over receipts stamped ten minutes apart: exit 2, DURACAO_DIVERGE, both numbers in the receipt. A note citing a file with no timestamp in its name: exit 2 again, fail-closed — a receipt without a stamp is not evidence, it is a name. Then green: eleven declared against ten point seven measured, rounding honest, exit 0. A note with no duration declared: exit 0, silence. And the regression suite over the instrument catalog stayed green throughout. One lesson earned its own fix mid-acceptance: the green round first printed "eleven minutes equals ten" — the guard compared correctly but displayed a truncated number, and a receipt that misreports its own arithmetic is a small lie with a long tail. The display now carries one decimal.
The counting family — guards, declarators, shell-checkers, thermometers grown one defect at a time — holds twelve tools on the disk.
Read before or after: The number that changed shells ; and The ending that hid the yellow.