Dog pregnancy calculator

Impossible calendar dates such as twenty twenty-six February twenty-nine fail with invalid_input and are not billed.

How canine gestation becomes a whelping date range

This calculator encodes that convention with integer civil-day arithmetic: due_date is mating_date plus gestation_days; due_start is mating_date plus gestation_days minus five; due_end is mating_date plus gestation_days plus five. When you leave gestation_days at the default of sixty-three, the window is exactly fifty-eight to sixty-eight days. Small and toy breeds sometimes deliver a day or two earlier than giant breeds, which is why the optional gestation_days field accepts any whole number from fifty through eighty so a kennel can pin a breed-typical mean without inventing a second landing. It does not replace progesterone timing, ultrasound confirmation, or a veterinarian’s advice for an individual bitch, and it never reads the server clock, so two machines in different time zones produce the same JSON for the same mating day.

Input contract, calendar validation, and response shape

A leap-year mating such as twenty twenty-four February first still lands on a real April day because February twenty-ninth is counted. Failed validation is never charged. POST a JSON body with mating_date, a real Gregorian calendar day in YYYY-MM-DD form. Aliases mating, breed_date, breeding_date, and date are accepted so spreadsheets and kennel forms can map columns without renaming. The day must exist: twenty twenty-six February twenty-nine, month thirteen, and day thirty-two of April are all invalid_input, as are missing values, empty strings, and any shape that is not four digits, a hyphen, two digits, a hyphen, and two digits. Optional gestation_days defaults to sixty-three and, when supplied, must be an integer from fifty through eighty inclusive; a fractional sixty-three point five is rejected so the due date is always a whole calendar day. On success the body echoes the normalized mating_date and the gestation_days actually used, reports range_days as five, and returns due_date (the point estimate), due_start and due_end (the inclusive window), due_range as a single display string of the form start to end, and a short formula reminder. Example: mating_date two thousand twenty-six March first with the default sixty-three days yields due_date two thousand twenty-six May third and the window twenty twenty-six April twenty-eighth through twenty twenty-six May eighth. Successful API calls use prepaid balance at the published $0.002 base price with unit item.

Where a dog pregnancy calculator earns its keep

Breeding kennels use a dog pregnancy calculator to turn a recorded mating day into a whelping-box deadline, a week of night watches, and a calendar hold for the veterinarian. Rescue and foster coordinators estimate when an unplanned litter may arrive so crates, milk replacer, and transport are ready before the first pup. Prefer a dedicated days-between tool when you only need calendar distance without the canine gestation model; prefer this capability when the output must be a whelping point estimate and the conventional fifty-eight to sixty-eight day window. The free browser tool runs entirely offline in your session; the API charges only successful solves at $0.002, keeps no durable copy of the mating date after the response, and returns the same ISO fields every time so local goldens match production.