A financial quarter is a quarter of a financial year, and a financial year does not have to start in January. A company whose year begins in April calls April to June its first quarter, so its Q1 and a calendar Q1 describe different months entirely.
That makes "Q1" ambiguous in any conversation spanning two organisations, and it is the reason financial reporting names the year end rather than assuming one.
Which year ends are common?
Several, and each has a reason behind it.
| Year runs | Used by |
|---|---|
| January to December | most companies, most countries |
| April to March | UK government, India, Japan |
| July to June | Australia, many charities |
| October to September | US federal government |
| Late January | many retailers |
The retail pattern is the most deliberate of them. Ending the year shortly after the winter trading peak means the accounts are drawn up when stock is at its lowest, which makes counting it cheaper and the balance sheet easier to verify.
The same logic applies elsewhere: an agricultural business ends after harvest, an education business after the academic year. The year end is chosen to fall at the quietest point rather than at a tidy date.
How is a fiscal year named?
Inconsistently, which is the part that causes real errors. Some organisations name a year for the calendar year it ends in and some for the one it begins in, so the same twelve months can be called two different things.
An April to March year is commonly written as spanning both years for exactly this reason, and anything abbreviated to a single year needs the convention stated somewhere.
Companies whose fiscal year runs ahead of the calendar make it stranger still, since a fiscal year can be named for a year that has not started yet. Nothing is wrong; the label is simply not a date.
What is a four-four-five calendar?
A way of making quarters comparable by making them the same length. Each quarter is thirteen weeks divided into months of four, four and five weeks, so every period ends on the same weekday and contains the same number of trading days.
That matters for anything measured weekly. Calendar months contain four or five weekends depending on where they fall, so a month-on-month retail comparison is partly measuring how many Saturdays it had.
The cost is that thirteen four-week periods do not quite fill a year. The shortfall accumulates until a fifty-third week has to be inserted every five or six years, and that year is not comparable to the others without adjustment.
What breaks in a year-on-year comparison?
Mismatched periods, mostly. Comparing a fifty-three week year against a fifty-two week one overstates growth by roughly two per cent before anything real has happened.
Moving holidays do the same on a smaller scale. An Easter falling in different quarters in successive years moves a chunk of trading between them, so both quarters look wrong and the half-year looks fine.
The defence is to state the basis alongside the number. A growth figure without the period definition is not verifiable, and most disagreements about performance turn out to be disagreements about which weeks were counted.
What should you check before quoting a figure?
The year end, the quarter definition and whether the periods being compared are the same length. Three questions, and any of them can move a growth rate by more than the growth being reported.
For anything crossing organisations, converting to calendar quarters first removes the ambiguity even if it means recalculating. A number everyone can locate on a calendar is worth more than one that needs a footnote.
Internally, the opposite applies. Keeping the organisation’s own periods is what makes its history comparable, and translating for outsiders is a reporting step rather than a change of basis.
Why do quarters exist at all?
Because reporting once a year is too slow to manage against and once a month is too noisy. Three months is long enough to smooth out individual weeks and short enough to act on.
It is also a regulatory rhythm in several markets, where listed companies report quarterly by requirement rather than by choice. That is why the quarter has become the default unit of business time even in organisations with no obligation to use it.
The cost is that quarterly reporting encourages decisions that land inside a quarter, which is a well-documented criticism and not one the calendar can fix.
Questions people ask
What is a stub period? The short accounting period created when a year end moves. It appears once and breaks any comparison spanning it.
Can a company change its year end? Yes, and the transition period is shorter or longer than a year, which breaks comparisons around it.
Does the tax year match the fiscal year? Not necessarily, and in several countries it does not for individuals.
Is Q1 always three months? In a calendar-based year, yes. In a week-based one it is thirteen weeks, which is slightly shorter.
Which quarter is a date in? Only answerable once the year start is known, which is the whole point.
Fix the year start, then the quarters follow. The fiscal year calculator works out which fiscal year and quarter a date falls in for any year start, and the quarter calculator and quarter date range calculator give the boundaries.