Why Your Resume Dates Have to Match Someone Else's Records

Employment dates are different from every other element of a resume, because they exist in someone else’s records as well as yours. A former employer’s payroll system has a start date and an end date for you, and those dates do not care what you wrote. If a check is run and the two disagree, the disagreement is factual and visible, so dates should be copied from documents rather than recalled.

That is the entire principle. What follows is how to apply it, and what to do when the accurate dates are inconvenient.

Where to get the real dates

In rough order of reliability:

Your first and last payslips for each role. These bracket the employment period as payroll recorded it.
The offer letter and any leaving or reference letter. Note that an offer letter states an intended start date, which is sometimes not the date you actually began.
Tax documents covering the relevant years, which show which employer paid you when.
A contract amendment if your role or terms changed mid-tenure.

Calendars, old emails and memory are all fine for reconstructing what you did. They are not good sources for when you were employed, and the gap between “when I started working there” and “when payroll says I started” is real often enough to be worth checking.

The distinctions that trip people up

Your first day versus your contract start. Occasionally a contract begins on the first of the month and you arrive on the fourth. Payroll will hold the contract date. Use it.

Notice period versus last day worked. If you were paid through a notice period you did not physically work, your employment end date is the end of that period. Writing the earlier date creates a gap that does not exist and understates your tenure.

Agency placements. If an agency employed you and placed you with a client, the agency is your employer for verification purposes. Naming only the client can read as a discrepancy when the client has no record of employing you. Name both.

Acquisitions and renames. If the company was bought or rebranded during your tenure, records may sit under either name. Note the change rather than silently using whichever name is better known now.

Contract-to-permanent transitions. These often appear as two separate records. Reflecting them as one continuous period is usually fine as long as you can explain the structure if asked.

Precision: months are the standard

Month and year is the normal level of detail, and it is enough. Day-level precision looks like anxiety and invites comparison against records that may be a day or two off for entirely mundane reasons.

The temptation runs the other way, though: years only, which quietly hides how long you were somewhere. “2023–2024” could be fourteen months or two. A reader who notices the pattern across every entry will assume it is deliberate, which is worse than the shortest tenure it was concealing. If you are weighing that trade-off deliberately, there is a real argument to have about months versus years rather than defaulting to the vaguer option.

When the accurate dates look bad

Correct dates sometimes produce an unflattering picture: a three-month role, a gap, several short stints. The response is not to adjust the dates. It is to decide what to include and how to frame it, which are legitimate editorial choices in a way that changing a date is not.

Options that stay honest:

Leave a short role off entirely, if it is old and not load-bearing. Omission is a selection decision, not a false statement — though be aware that a background check covering a fixed number of years may surface it anyway, so omit only where you are comfortable explaining the omission.
Group early roles under a single heading with a combined date range, listing the titles inside. Common and readable for anything more than a decade back.
Name the reason briefly where it is short and unremarkable. A one-line note on a fixed-term contract or a redundancy stops the reader inventing an explanation.

What none of these do is move a date. A date you moved is the kind of thing that turns a manageable conversation about a short job into an unmanageable one about accuracy.

Two roles at one employer

Promotions create a small formatting problem: one employer, two titles, two ranges. Show the employer once with the overall period, then the titles with their own ranges nested under it. The nested ranges should add up to the outer one without gaps or overlaps, because a careful reader will check that arithmetic and an inconsistency there looks careless at best.

Dates and the rest of the resume

Dates constrain everything above them. A summary claiming extensive experience sits directly above a date range that either supports it or does not, which is why an AI-written summary can end up contradicting the timeline on the same page. Similarly, a bullet claiming you took something from concept to launch inside a five-month tenure should be plausible against the calendar.

Read the dates last, then read the rest of the page against them. It is the cheapest consistency check available.

Never let a tool touch them

Dates are fixed fields, not prose. An AI resume tool reformatting your history may standardise, round, or drop a month, and it has no reason not to. Copy them in at the end, from your documents, and treat them as the part of the draft that gets checked separately from everything else. If you keep a facts file, the dates in it should have come from payslips the first time you wrote them down, so you never have to reconstruct them again.