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ISO 8601 & bankgiro OCR toolbox

Test ISO 8601 dates, durations and intervals with @0dep/piso, and validate or generate Swedish bankgiro OCR references with ocrgenerator — all in your browser, with a local history of what you tried. Looking for the process engines? Run BPMN · Evaluate DMN.

ISO 8601

Try 2024-W09-4, 2024-060T08:06:30+02:00, -P1D, P1Y2M3W4DT5H6M7S, 2007-03-01/2007-04-01, R-1/2009-07-01T00:00Z/P1M. Zone-less input is local time unless UTC is enforced — the same rule bpmn-elements applies to timer cycles.

Bankgiro OCR reference

Validation reports the modulus 10 outcome under the soft, hard and variable-length algorithms, plus fixed length when one or two agreed lengths are given. Generation keeps the digits of the input — e.g. Customer007:Date2019-12-24:Amount$200 — and appends the length control and check digits; a fixed length pads with zeros or caps from the left. Bankgirot accepts 2–25 digits, plusgirot 5–15.

History

Your previous attempts, kept in this browser’s local storage only — click one to restore its input and options and run it again.

Nothing yet — parse a date or check an OCR reference and it shows up here.

    Two small zero-dependency libraries, in your browser

    This page is a playground for two of the zerodep packages. @0dep/piso parses ISO 8601 as declared on Wikipedia — calendar, week and ordinal dates, durations with a leading minus, and repeating intervals — and reports what the string means: its components, the next start and expiry relative to now, week number and epoch. ocrgenerator validates Swedish bankgiro OCR references against all four modulus 10 algorithms and generates one from any string. Everything you type never leaves the browser; your attempts are kept in local storage so you can revisit them, and after the first visit the page works offline.

    Is any data transmitted when I parse or validate something?
    No data is transmitted. This is a static page and both libraries run entirely in your browser — the strings you test never leave your machine. The page makes no network requests with your content, and its Content-Security-Policy blocks requests to any other origin. The site is open source, so you can verify this in the code.
    Where is my history stored?
    In your browser’s localStorage, on this device only. Nothing is synced or uploaded — clear it with the button on the page or by clearing site data. The last 50 distinct attempts are kept.
    Which ISO 8601 forms are supported?
    Dates including week dates and ordinal dates, basic and extended notation, fractional seconds and time zone offsets; durations with the designators P, Y, M, W, D, T, H, M and S including fractions on the smallest unit and a leading minus; and intervals with start/end, start/duration, duration/end and repeat prefixes such as R5/P1Y/2025-05-01T13:00:00Z.
    What is a bankgiro OCR reference?
    A Swedish invoice number validated with modulus 10 (Luhn). Bankgirot accepts four variants — soft, hard, variable length with a length control digit, and fixed length agreed with the bank. The generator builds a reference from any string, keeping its digits and appending the length control and check digits; the validator reports how the reference fares under each variant.
    What libraries power the page?
    @0dep/piso parses the ISO 8601 dates, durations and intervals — it is the same parser used by bpmn-elements for timer events — and ocrgenerator validates and generates the OCR references. Both are zero-dependency packages from the zerodep org on npm.

    Don’t take our word for it — the whole site is open source: github.com/zerodep/0dep.se.