A name with two ideas in it.

Both of them are why we exist, and how we work.

Long before clocks, every civilization that looked up planted a rod in the ground and read its shadow. The Greeks called it the gnomon, from the verb to know. It was the one that knows. You read it to tell the time, the season, your place on the earth.

The one that knows

It worked because it didn’t move. While the sun crossed and the year turned, the gnomon stood still and turned all that motion into one clear shadow you could act on. That’s what we’re built to be, the fixed point that turns everything moving around you into a clear reading you can act on, so you stay on your best path toward what you’re after.

Growth that doesn’t distort

But knowing where you stand is only half the work. Centuries later, geometers gave the same word a second meaning. To them, a gnomon was the piece you add to a shape to make it bigger without changing its shape at all. It’s how a nautilus grows, adding a bigger chamber year after year while the spiral stays the same the whole way out.

To grow what you’ve built without changing what makes you, you.

Those are the two halves of the work, and the two halves of the name. We give you a clear, steady read on where you stand, and we help what you’ve built keep growing without losing what makes it yours. Tax is where it starts, because tax is where the clearest readings and the most avoidable mistakes live. Planning is where it goes.

Who’s behind it

Mark Gallivan, EA, CFP®

Founder · Gnomon Planning

Enrolled Agent (EA) CERTIFIED FINANCIAL PLANNER® (CFP®) MBA · Arizona State University B.S. Business Management · University of Minnesota

Mark founded Gnomon Planning in Phoenix, Arizona, on a simple conviction. Most people’s money is advised in pieces, and the pieces rarely agree. He built the firm to be the fixed point, reading the whole picture and keeping it moving in one direction, tax first, then the planning that follows from it.

What’s an Enrolled Agent?

An EA is the highest credential the IRS awards, a federally licensed tax practitioner with unlimited rights to represent taxpayers before the IRS. The license is earned specifically in tax, and it’s national, not state-by-state.

See where you stand.

The Gnomon Diagnostic is the first reading, a clear look at your situation and what to do next. It’s yours to keep, either way.

Start Your Diagnostic