The firm

Accountants and engineers, on the same ledger.

We built the software we always wanted to run books on — then we started running books on it.

How we work
01 — Why we built it

The close got earlier. Then it disappeared.

DayZero is the point on the calendar where the close stops being an event. Getting there took four stages.

Day 15Where we started. Books closed two weeks after month-end — too late to catch anything before it became history.
Day 5We built software to shrink it. Automated reconciliation and categorization cut the close from weeks to days.
Day 1Then to one day. Continuous drafting and flagging meant the close was never more than a day behind reality.
Day 0Now. The close isn't a date anymore — the books are simply always current. That's the name.
02 — How we're built

A firm that ships software.

We are not a software company that added services, or a firm that bought a tool. Every engagement runs on the platform — our accountants close books on the same product our engineers maintain, against the same ledger.

That loop is the whole model. Every fix an engagement needs — a missing reconciliation rule, a report a client asked for, an integration a close depended on — ships back into the platform, so the next engagement starts further ahead than the last one did.

03 — Where we come from

Investment banking. Private equity. Engineering.

Our backgrounds span investment banking, private equity, and engineering. We know what institutional investors expect to see, because we've been the ones asking.

04 — Careers

We're not hiring right now.

No open positions at the moment. If you want to talk about a pilot — or anything else — reach us at hello@ondayzero.com.

Meet the team that builds what it runs.

Schedule a pilot and talk to the accountants and engineers who wrote the software.