Spreadsheet Day

Oct 17

The spreadsheet continues to change the world

After 43 years, the spreadsheet still reigns supreme within the world of analysis and modeling. To celebrate Spreadsheet Day, we wanted to reflect on the milestones that made the spreadsheet so popular—and powerful.

Over the past 40+ years, the world of analysis has changed faster than the spreadsheet. Data grew more abundant and dispersed, which means every analysis starts with gathering data from all over. Analysis became more collaborative, making versioning essential. And teams became more connected, making integrations with tools like Slack and Notion critical to modern workflow. If we asked any analyst today what their dream spreadsheet could be, they'd say: “I'd want one connected to live data and fully embedded in the ways our teams work.”

So that's what we're doing at Equals.

We're creating a next-gen spreadsheet made for modern analysis. We created this company with tremendous respect and admiration for all those who helped the spreadsheet evolve. And with Equals, we hope to keep the legacy going.

Ben and Bobby
Co-founders of Equals

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1939
George Stibitz designs the Complex Number Calculator (CNC) at Bell Telephone Laboratories. Many say the CNC is the first demonstration of remote access computing.
Operator at Complex Number Calculator (CNC).
Credit: Computer History
1943
John Mauchly and J. Presper Eckert begin building the ENIAC computing system—it does more calculation in ten years of operation than all of humanity had done before then.
1944
Howard Aiken completes the Harvard Mark 1, a room-sized, relay-based calculator that could produce mathematical tables.
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1948
Frederic Williams, Tom Kilburn, and Geoff Toothill develop the “Manchester Baby” or the Small-Scale Experimental Machine (SSEM) that runs the first computer program.
1952
Kohler's First Edition Dictionary for Accountants publishes the word “spreadsheet,” which is already commonly used in the field. The name comes from two facing pages on a paper “spread” used in accounting ledger books.
1954
IBM releases the IBM 650, a mass-produced computer that was popular with universities. It became the de facto computer for the first generation of programming students.
1961
Richard Mattessich first writes about the concept of an electronic spreadsheet in his paper “Budgeting Models and System Simulation.”
1968
Douglas Engelbart gives a landmark live demonstration at the Computer Society's Fall Joint Computer Conference, later called the “Mother of All Demos.” The demonstration showcases key elements of modern personal computing for the very first time, and the computer mouse demo inspires Dan Bricklin's electronic spreadsheet a few years later.
1969
Rene Pardo and Remy Landeau develop a commercial electronic spreadsheet called LANPAR (LANguage for Programming Arrays at Random) to help companies like Bell Canada and AT&T revise the cells in their budgeting forms more easily.
1971
John Blankenbaker creates and sells the Kenbak-1, widely considered to be the world's first personal computer.
Hewlett-Packard releases the HP-35, a handheld calculator capable of doing the scientific calculations that only computers could at the time. HP-35 becomes a leader in handheld calculators for over two decades.
1974
Xerox PARC Alto, a groundbreaking computer with graphical user interface, debuts. The Alto uses windows, icons, and a mouse and applications like email and word processing. It's widely regarded as the inspiration for Apple's early computers.
1977
Apple's Apple II, a popular personal computer, is released. It becomes the first personal computer that can use an electronic spreadsheet program.
1978
Dan Bricklin, a student at Harvard Business School, comes up with the idea of using an electronic spreadsheet on a personal computer to help him with his finance class.
Source: Harper's, 1984
1979
Dan Bricklin and Bob Frankston release VisiCalc, the first electronic spreadsheet program for the Apple II personal computer, on October 17. The name brings together two words crucial to the program: visible calcuation.
Source: Harper's, 1984
1980
Computer Associates release the SuperCalc, a different spreadsheet program that's compatible with the Osborne 1 computer and can iteratively solve circular references.
Source: Wikipedia
1982
Microsoft creates the Multiplan, a spreadsheet application. Because it's not as successful as other spreadsheet applications at the time, Microsoft replaces it with the Microsoft Excel in a few years.
Source: Wikipedia
Dan and Bob appear on the cover of Inc. Magazine and are featured in an article about the VisiCalc.
Source: Bricklin
Mitch Kapor and Jonathan Sachs found the Lotus Development Corporation, a company that releases the seminal Lotus 1-2-3 spreadsheet application a year later.
1983
Lotus Development Corporation releases 1-2-3, a new spreadsheet application for Microsoft DOS that does $53M in business in the first year alone.
Source: Harper's, 1984
Microsoft begins “Project Odyssey,” a special project that would eventually create Microsoft Excel. The team, led by Doug Klunder, shifts from building for PC to Mac's graphical interface and focus on increasing the speed of recalculation. Their team motto is “Recalc or die.”
1985
Microsoft releases Excel 1.0, a spreadsheet application, for Macintosh. It becomes the most popular spreadsheet of all time and the backbone of modern business.
Source: Britannica

Think about a world without Excel. That's just impossible for me.
Satya Nadella
CEO of Microsoft

Image credit: Fortune
Image credit: Internet Archive
1989
Microsoft Excel begins to outsell Lotus's 1-2-3 application.
Source: Harper's, 1984
1991
Lotus releases Lotus Improv, a now-discontinued spreadsheet program that inspires the modern-day pivot table feature.
Source: Wrap Text, 2022
1992
Bill Gates reviews Microsoft Excel's 1900 Leap Year Bug for the first time. Excel incorrectly treats the year 1900 as a leap year to be compatible with the Lotus 1-2-3, which has the same bug. The bug still exists today because changing it would wreak havoc on dates, weekday functions, and serial date compatibility.
1993
Microsoft Excel releases Visual Basic for Applications (VBA), a programming language that allows users to solve different mathematical equations within spreadsheets.
Source: Wikipedia
1994
Microsoft Excel releases the Pivot Table feature.
Source: Wikipedia
1996
Steve Jobs appears on a documentary for the Japanese TV network NHK and says that the VisiCalc was “what really drove—propelled—the Apple II to the success it achieved.” The VisiCalc becomes known as the Apple II's first “killer app.”
Source: Bricklin
1997
Microsoft introduces Clippy, also known as the Excel Office Assistant, to help users with the Microsoft Office Suite of applications.
Source: The Verge, 2019
2004
Genetic scientists find that Microsoft Excel incorrectly translates some gene names into calendar dates. It takes another 16 years before the HUGO Gene Nomenclature Committee creates new guidelines to change how to name genes (rather than stop using Excel).
2006
Danielle Aubert, Detroit-based graphic designer, publishes A Year's Worth of Drawing Exercises in Microsoft Excel.
Source: Danielle Aubert
Google releases Google Sheets and Google Docs in beta. The web-based spreadsheet and document applications become popular for real-time collaboration.
Source: Endgadget, 2021
2007
Microsoft Excel switches from a proprietary binary file format called Excel Binary File Format (.XLS) to Office Open XML (informally called OOXML), a new standardized file format.
Source: Wikipedia
2010
Spreadsheet Day is founded on October 17 by Debra Dalgleish, owner of an Excel resource hub called Contextures. The logo is created in Excel using the OCT column heading and row 17.
Image credit: O'Reilly

Happy Spreadsheet Day! May all your calculations be correct.
Debra Dalgleish
Creator of Spreadsheet Day
2020
ESPN broadcast the World Excel Championships as part of their live Esports programming for the first time.
The first Financial Modeling World Cup (FMWC), a financial modeling competition sponsored by AG Capital and Microsoft, debuts.
Source: Wikipedia
Microsoft Excel releases LAMBDA, which makes Excel Turing-complete for the first time ever by allowing users to write any computation in Excel's formula language.
Source: Microsoft, 2021