For the home safety owner

The hallway smoke alarm reads made in May 2017 on the back, the CO alarm by the basement stairwell reads made in June 2019, and the fire extinguisher under the kitchen sink reads made in November 2014. Three labels, one board: one sentence to Muse in ChatGPT, my hallway smoke alarm says made in May 2017, and the month and day on the stamp become the start of that alarm's ten-year clock. The board carries the house's safety rows: alarms tested on the 1st of every month, batteries once a year, each alarm replaced 10 years from the date stamped on its back, and the extinguisher with its gauge watched every month and its 6-year maintenance and 12-year hydrostatic test counted from the same stamped date.

The monthly test is the heartbeat. The house test day is the 1st, and one sentence when it happens is enough: tested October 5, 2026, all three answered. A test told late still pays its month: October 5 pays October, and the next window opens November 1. A test told September 28, 2026 is the other shape: October's window was never paid, so on October 7 the row reads due, 6.5 days late. The 1st stays the 1st; a late test does not slide the date.

The batteries carry their own yearly row. A nine-pack went in on December 1, 2025, $14 at the hardware store, and the yearly clock reads next December 1, 2026, 54.5 days out as of October 7. One row for the whole house, and the 3 a.m. chirp never has to be the reminder; the row is.

The replace-by date is the headline row, and its clock starts from the date printed on the back, not from the day you told your agent. The hallway alarm's stamp reads May 15, 2017, so the row reads replace by May 15, 2027, about 7 months of runway. The CO alarm's stamp reads June 15, 2019, replace by June 15, 2029. An older alarm shows the other side: a stamp of May 15, 2016 reads replace by May 15, 2026, already past, 145.5 days late, almost 5 months overdue, and the row says so plainly.

And where the stamp's date goes is a safety promise, not paperwork. If your agent ever writes the manufacture date in the wrong spot inside the job, Maintenance Due does not quietly save a replace-by date nine years late: it says so plainly, and tells the agent where the date goes, beside the interval, not inside it. The corrected write goes through on the spot, and the row reads replace by May 15, 2027. A 2017 alarm would otherwise have read 2036, ten years from the day the house was told, not from the day the alarm was made. Nine years of false comfort is the failure the board refuses. It will not guess quietly in the unsafe direction.

The extinguisher carries its dates the same way, from the stamp on the tank: November 1, 2014. The 12-year hydrostatic test reads November 1, 2026, 24.5 days out as of October 7, and the 6-year maintenance lands on the same day this year, because six goes into twelve. After this fall the two clocks keep their own rhythm, the 6-year line coming around twice as often as the 12-year line.

The gauge gets its look on the 1st too, and the recharge row reads the needle. Until a reading is told, the row waits and names the line: the needle under 80. A gauge that read 100 right after the last recharge and 92 on October 5 leaves 12 points above the line, falling about 8 points in 126 days, which puts the line around April 12, 2027. A needle that reads 78 is under the line: due now, 2 points under. Recharge, tell Muse the date and the receipt, and the row clears.

On October 7 the owner asks Muse what's due in the house this month. The rows come back in one answer: the monthly tests paid on October 5, next window November 1; the hydrostatic test and the 6-year maintenance on November 1, 24.5 days out; the batteries on December 1, 54.5 days out; the hallway alarm's replace-by waiting until May 15, 2027; the gauge 12 points above its line. Nothing overdue, and the board says that plainly too.

The safety rows carry the headline, and the ordinary calendar rows keep the house running around them: a radon test kit on a yearly clock, run January 6, 2026, next January 6, 2027; the dryer vent on a two-year clock, cleaned March 18, 2025, next March 18, 2027. The same plain clocks: a yearly clock stays yearly, a two-year clock stays two years, and a late chore does not slide the date.

The house gets the observation habit too. A chirp from the upstairs alarm, a scorch mark by the stove, the dryer taking a second cycle: the observation goes to Muse in the same breath as the date. Muse keeps each one as a note on that row, so the house's history stays with the house. The spiral notepad on the fridge can retire.

Outbound, the board calls ChatGPT. One subscription and ChatGPT hears when the hydrostatic test lands on the due board: a signed webhook names the job and how late. An agent that speaks MCP can hear the same board. The ping arrives without anyone asking.

Every row logged stays in the service log: the monthly tests with their dates, the battery packs at $14, the recharge with its receipt and the reading beside it. So the day the house sells, one word, archived, is enough. Muse archives the alarms and the extinguisher and the due board drops them that day, and the history stays: years of test dates, what the gauge read at each check, the receipts beside them. If the sale falls through, one ask puts it back on the board.

One line, said plainly: Maintenance Due is a personal due board and service log for the house. It keeps the notes you give it. The alarm was made when it was made, and the board counts the days and the readings you tell it.

The house log on /home-maintenance-checklist shows how calendar rows look. The Muse prompt lives on /for-your-agent. Free.