Releases 1.0.0 – 1.59.4

Newest first. Three numbers, and which of them moves says what happened to you rather than how much work it was.

The first moves when something that worked stops working: a query that used to answer and now does not, a saved list that will not load, a link you shared that no longer opens what it opened. It has never moved, and that is the whole of what it is for.

The second moves when the page answers something it could not answer before, or answers it better than it did. New grammar is the usual reason. A correction is the other, and a correction is not a break even though the answer changes underneath somebody: "days be christmas" used to say 154 days and now says nothing, because it was reading Belgium out of the word "be", and taking that away left the page more right rather than less useful. An answer that gains a drawing of what it just said counts here too.

The third moves when nothing you type comes back any different.

Numbers get skipped when it takes more than one commit to introduce a release, so only the release from the last commit goes out.

1.59.431 July 2026

The sun does set in Reykjavik

dawn in reykjavik 21jun2026the sun does not set · 64.15° is inside the Arctic circleit never gets dark enough for dawn · 64.15° is too far north for the sun to reach 6° below the horizon
Both old lines were false. sunrise in reykjavik answers 2:55 am on that day, and the Arctic circle begins at 66.56°.
Dawn is measured six degrees further down than sunrise, so it can go unreached where the sun plainly rises and sets.

1.59.331 July 2026

"under" now means under

first prime under 10010197
first prime below 500503499
next prime before 33893,3913,373
last prime after 33893,3733,391 · read as "after", which is the word that names a side
The preposition was matched and thrown away, so only the ordinal decided, and first counted upwards.

1.59.231 July 2026

The country you named counts for every kind of count

how many weekdays in july in the us23 weekdays22 working days
weekdays until christmas in the usin 110 weekdaysin 106 working days
working days between 1 jan 0001 and 1 jan 9999 in the us2,498,376 working days after 5.5sthe same answer in 0.4s
The country was taken off the end of the line and then ignored, so the words vanished from the query and changed nothing. The range form had been reading it all along.

1.59.131 July 2026

Boxing Day exists again in Britain and Canada

what day is 28 dec 2027 in the ukTuesday · a working day in the UKTuesday · Boxing Day, observed in the UK
working days between 24 dec 2027 and 4 jan 2028 in the uk5 working days4 working days
23 dec 2027 + 5 business days in the ukFri, 31 Dec 2027Tue, 4 Jan 2028
Christmas and Boxing Day both wanted the same substitute Monday and only one could have it, so two years in seven Boxing Day shut nothing in Britain or Canada.

1.59.031 July 2026

A base answer pastes back in

1715 in octal echoes 1,715 in base 8, and typing that back was told that a base writes whole numbers. The page was disowning its own printing a moment after doing it.
A comma groups or it is a decimal point, told apart by whether the groups are threes. 1,715 is a number and 1,5 is one and a half.

1.58.031 July 2026

Whether two places keep the same clock

is dc and nyc the same timezone, do dc and nyc share a time zone, is tokyo the same timezone as seoul.
Three answers, not two. Same zone is yes. Different clocks is no, with the gap. Different zones keeping the same clock is neither, and it says which: Tokyo and Seoul agree all year, Phoenix and Los Angeles agree today and part in November.

1.57.031 July 2026

A second opinion on every holiday

The rules are now checked against two published sources instead of one, because they are wrong in different places and a rule both agree with is a rule worth trusting.
It found four things on its first run. Poland made Christmas Eve a non-working day in 2025 and this had not heard. Switzerland keeps four holidays nationwide, not the seven claimed here. The Netherlands was missing Liberation Day and Sweden was missing Midsummer.

1.56.031 July 2026

Nineteen more countries know their holidays

France, Germany, Italy, Spain, the Netherlands, Poland, Portugal, Sweden, Belgium, Austria, Switzerland, Greece, Ireland, Denmark, Norway, Finland, Czechia, Brazil and Argentina.
what day is 14 jul 2026 in paris says Bastille Day. 10 business days in france from now skips what France skips.
Rules rather than dates, and all 483 of them are checked against published lists. Only three countries move a holiday off a weekend, and Argentina moves four of its days to make a long weekend.

1.55.031 July 2026

New Year's Day is a holiday again

The 1st of January had been counting as a working day in all three countries. The lists that say which days shut an office spell it "new years" and the lookup only answered to "newyears", so it quietly matched nothing.
31 dec 2025 + 1 business day in the us gave you the 1st. It gives you the 2nd.
The check that compares these rules against published holiday lists now covers every day, in all three countries, which is how this surfaced.

1.54.031 July 2026

The holiday has a name, and the city keeps its own

what day is 1 jul 2026 in toronto says Canada Day. The place carries its country, so you do not have to add one.
The day off moved off a weekend says so: what day is 3 jul 2026 in new york is Independence Day, observed.
what day is it in quebec said Friday in Toronto. Quebec keeps Toronto's clock and is not Toronto, and the answer no longer renames it.

1.53.031 July 2026

Several numbers, one question

are 4831 and 5 both prime numbers, are 7, 11, 13 prime. The answer says which of them are, since a bare no throws away the half you were asking about.
Commas and spaces both separate, and 4,831 and 5 is two numbers rather than three.

1.52.031 July 2026

Boston is 300 km from New York again

distance from boston to new york answered 0 km. Boston keeps New York's clock, and the distance was reading the clock's position rather than the city's.
The hundred-odd cities that borrow a zone now carry their own coordinates, and the answer names the city you typed rather than the one whose clock it keeps.
Chelyabinsk joins the list in the same pass.

1.51.031 July 2026

The suggestions stop repeating themselves

The chips drew their places from a list of ten, so Singapore and Paris came round every other visit and the suggestion read as a fixed one rather than a generated one.
Ninety-four cities now, which puts a repeat about one draw in four thousand. Barnaul and Vladivostok are in there, along with Tbilisi, Reykjavik and Hobart.

1.50.031 July 2026

The app stops changing width

The column is 720px on every visit. It used to be as wide as whatever happened to be inside it, so a long saved query gave you a wide app and a short one squeezed it under 450px, on the same screen, with nothing you did to explain the difference.
The heading, the box and the footer now line up down one edge. The word calculingo at the top was floating in the middle because the bar holding it was only as wide as the word.

1.49.031 July 2026

The enter key draws itself

The key beside just press enter on the About page carries its own size and colour, so a stylesheet that has not arrived yet costs you a border and nothing else.
Before this it was an 11-pixel arrow that filled the width of the page in solid black whenever the CSS lagged behind the HTML.

1.48.031 July 2026

A new icon, and a keyboard key you can see

The tab icon was a calendar, which stopped being the truth some while ago. It is an equals sign now, drawn rather than borrowed from the emoji set.
The About page shows you how to save a query, with the enter and return keys drawn inline as keys.

1.47.031 July 2026

The chips show the whole of it

The suggestions under the box sat at eight kinds of question while seven more arrived behind them. You were shown a date-and-unit calculator and could have been forgiven for thinking that was all of it.
Fifteen kinds now, twelve of them per load: distances, other calendars, weekdays, bases and Roman numerals, primes and factors, statistics, and the sentences where two things make a third, as well as the eight that were already there.
The unit chip draws on the whole table rather than the corner of it that existed in July: angles, energy, bits and line speeds turn up alongside kilometres and pounds.

1.46.031 July 2026

Percent change

percent change from 120 to 150 is +25%. The three orders already here take a part and a whole; this one takes a before and an after.
Say the direction and the figure drops its sign, so percent increase from 120 to 150 is 25%. Say the wrong direction and the numbers win, with a note saying which way it went.
Two rates sit a number of points apart as well. percentage points from 15% to 20% is +5 points, and a rise of a third on the old rate.

1.43.031 July 2026

Primes, factors and divisibility

is 91 prime answers no, and 7 × 13. You wanted the 7 × 13 more than you wanted the no.
factors of 360 lists the two dozen divisors. prime factors of 360 is 2^3 × 3^2 × 5.
next prime after 100 is 101. is 360 divisible by 8 answers yes and 45; ask it about 100 and you get no and 12 remainder 4.
Above a trillion it declines rather than spend a second dividing while you type.

1.40.031 July 2026

How spread out a list is

stdev of 1 2 3 4, variance of ..., mode of 1 2 2 3. Divided by n-1, and the answer says sample so you can see which divisor it picked.
Ask for the other divisor by name: population stdev of 1 2 3 4.
p90 of ..., q1 of ..., iqr of .... Half a dozen definitions of a percentile disagree on short lists, so the answer names the one it used.
A mode may be two values or none. Where nothing repeats, it says so instead of handing back whichever value came first.

1.37.031 July 2026

Bases, and Roman numerals

255 in hex, 0xff in decimal, 255 in base 7. Any base from 2 to 36.
19 octal in decimal tells you that 9 is not an octal digit.
1994 in roman is MCMXCIV. Type IIII and you get 4, with a note that the proper spelling is IV.
dec and oct stay December and October.

1.34.031 July 2026

Fuel economy

30 mpg in l/100km, 8 l/100km in mpg. Distance over fuel and fuel over distance sit upside down from each other, so no factor turns one into the other.
Which gallon is a fifth of the answer: 30 mpg uk in l/100km. Leave it out and you get the US one, and the answer says so.
500 km at 8 l/100km is forty litres. 500 km on 40 litres is the economy you managed.

1.31.031 July 2026

Bits, line speeds and download times

1 byte in bits, 100 mbit in mb. Decimal and binary bits both.
100 Mbps in MB/s. A capital B is a byte and a small one is a bit, which is what the industry writes and the second place here where the case of a letter changes the answer.
5 GB at 20 Mbps is 33 minutes 20 seconds. The same file at 20 MB/s takes four minutes, and that eight is why anybody ever cared about the difference.
5 GB in 10 minutes is the rate a line would have to be.

1.28.031 July 2026

Energy

100 kcal in kj, 1 kwh in joules, 1 btu in j, 1 therm in kwh. A kettle is rated in watts and billed in kilowatt-hours, and neither used to reach the other.
250 Calories is a thousand times 250 calories. A food label's capital C is the whole of the difference.
100 w for 3 hours is 0.3 kwh. 1 kwh at 100 w is the ten hours your battery lasts.

1.25.031 July 2026

Angles

90 degrees in radians, 1 turn in degrees, 200 grad in degrees. The sums have answered trigonometry in radians since they were written, which left you holding a unit you had not asked for.
Arcminutes and arcseconds come with it, and 90° in radians reads the sign.
40°42'46" in decimal degrees, and back the other way with 40.7128 degrees in dms. 5'10" in cm is still a height: the degree sign tells the two apart.

1.22.031 July 2026

Lakh and crore

2 crore rupees in usd, 5 lakh inr in usd, half a crore, 2 lakh km in miles.
1 crore answers 1,00,00,000, grouped in twos the way you say the word, with 10,000,000 underneath. Rupee amounts get the same grouping.
1 crore in lakhs is 100 lakh. 1 thousand is a thousand, where it used to be the year 1000.

1.19.031 July 2026

Holiday names finish themselves

Type next ram and adan appears in grey. days until chris finishes as christmas, hanu as hanukkah.
Nothing about those spellings is guessable from outside, and the page never shows you the list. Same argument as the city completion.
A city still comes first, so st p is Saint Petersburg. It leaves a whole word alone, so eid stays eid.

1.18.031 July 2026

The same day in another calendar

today in the hebrew calendar, hijri date, christmas in the islamic calendar, thai date. Ten calendars, all of them your browser's own.
Each answer says where that calendar's year count starts, since that is the one thing about a strange year number worth knowing.
1 muharram 1448 reads back the other way, which is how you type a date off a printed invitation.
The Chinese calendar is missing, for the reason Lunar New Year is: the runtime's answer runs a day out when a new moon falls near midnight in China.

1.15.031 July 2026

Which day of the week

what day of the week is 4 jul 2026, what day is christmas, christmas falls on what day, what day is it.
what day is 25 dec 2026 in the us says it is a holiday there. Name no country and you get weekday or weekend, since without one there is no telling who is at work.
what day is it in tokyo reads the date off the clock there. Los Angeles is sometimes still on the day before.

1.12.031 July 2026

How far apart two places are

distance from tokyo to london, how far is tokyo from london, distance tokyo london, how far is tokyo.
It reads the coordinates sunrise already uses, so it ships no new data to answer you.
Name the unit at either end: distance from tokyo to london in miles, how many km from tokyo to london.
The detail line carries the bearing the course sets off on, which is why a long flight looks bent on a flat map.

1.9.030 July 2026

Weights of things you cook with

200g flour in cups, 2 cups flour in g, 1 cup butter in g. Two dozen ingredients, in grams per US cup.
A cup of flour is not a fixed quantity of flour, so the answer says the figure is nominal.

1.8.030 July 2026

A rate on a past day

100 usd in eur on 1 jan 2020. The ECB has published a daily series since 1999 and the proxy will fetch a day of it.
It publishes on business days, so a weekend or a holiday answers with the last day it did publish. The answer says which day it used, because a rate is data with an age.

1.7.030 July 2026

Every

every friday in august, every 2nd tuesday until december, every last friday in 2027. You get the count and the dates.
every 5th tuesday in 2027 names the four months that have one.

1.6.030 July 2026

The length of an afternoon

hours between 9am and 5pm, minutes between 9am and 5:30pm. An end before its start is the next day, so hours between 10pm and 6am is a night shift of eight.
Each end may name its own zone. hours between 9am london and 5pm tokyo answers nought, the two desks being at the same instant.

1.5.030 July 2026

Working days that know where the office is

Name a country and the count skips its holidays as well as its weekends: 1jul2026 + 5 business days in the us steps over the 3rd, because the 4th falls on a Saturday that year.
Britain and Canada add a substitute day after a holiday that lands on a weekend, so Christmas 2026 shuts them the Monday after Boxing Day and shuts the States on the Friday before.
Ranges take a country too: business days between 20dec2026 and 5jan2027 in the uk.
Four bank holidays that had no other name are now dates in their own right: early May, spring bank, summer bank and Victoria Day.

1.4.030 July 2026

Thirty-seven ways of asking that did not work

Amounts in the size you say them: 3 mil rub in dollars, half a million, 10 grand, a dozen.
Currencies by their plain name: rubles, yuan, zlotys. Hundredths too: 50c in usd, 1 gbp in pence.
Money that no longer exists, at the rate fixed when it went: 100 dem in eur, 1000 rur in rub.
Questions put the way you would say them: convert 100 usd to eur, how many miles is 20 km, 100 usd = eur.
Time zones by acronym and by offset: 3pm EST to CET, 3pm utc+2 in tokyo, meeting at 9am pst in berlin.
Sunrise, sunset and twilight anywhere: sunrise in tokyo tomorrow, day length in london.
Area, pressure, power, light-years and teaspoons. Heights in two units at once: 5ft10 in cm, 180 cm in ft in.
Weekends, quarters, ISO week numbers, the nth day of a year, ages from a birth date, and whether a year is a leap year.
The lunar holidays. Your browser already carries the Islamic and Hebrew calendars, so no shipped table can run out.
Unix time, read and written. Fractions, decimals and percentages of one another. Combinations, gcd, and averages of a list.

1.3.028 July 2026

Fewer round trips, and the licence written down

Calculingo serves its own font. Google no longer sees your visit, and each font file carries the hash of its own bytes in its URL.
Your browser keeps calc.js and calc.css for a year and re-fetches only the page that names them, so a second visit downloads little.
Cloudflare sends the Content-Security-Policy as a header, so it covers the page from the first byte.
Both served files state their licence and who owns them.
A line above the box tells you what the app is for. It fades after three seconds.

1.2.027 July 2026

More words it knows, and a currency list you can search

The Easter cycle, the statutory days, this, and the nth weekday of a month.
Arrow through the currency list, preview a choice in the line, take it with Enter or Tab.
Fortnights, ISO weeks, month spans and data sizes. Hours and minutes can drive the count.
A time answer names the place you typed and the date it lands on.
A half-typed query stays quiet.

1.1.026 July 2026

First round of fixes

what time is it in tokyo answers, the same as time in tokyo.
Type three letters of a city and the rest fills in.
A second feed covers the currencies the ECB dropped, the rouble among them.
3 hours counts hours, and from anchors an offset to a date.

1.0.025 July 2026

First release

A date calculator you type at in plain words. It reads dates in whatever shape they arrive and measures the gap between them.
Four grammars share the box: dates, time zones, units and money. Each stays quiet unless the query is its own.
A history list keeps what you asked. Click an answer to copy it.