Support

Using it

How do I change the time?

Three ways. Drag along the coloured timeline band to scrub through the day. Tap the chevrons either side of the clock to step a quarter of an hour. Or tap any event in the list — sunrise, golden hour, sunset — to jump exactly to that moment.

NOW returns you to the present.

How do I change the date?

The chevrons either side of the date move a day at a time. Tapping the date itself opens a calendar.

How do I read the dial?

You are standing at the centre. North is up, the rim is the horizon, and the middle of the dial is straight overhead. The sun's path for the day is the gold arc; the further from the centre it sits, the lower the sun. The dark wedge is the direction shadows fall, and it grows longer as the sun drops.

Why does the sunrise time differ from my weather app?

Two likely reasons. Gnomon uses the standard convention of the sun's centre at −0.833° altitude, which accounts for the sun's own width and for atmospheric refraction; some low-precision tables run a minute or two short of this.

More likely: you have drawn a skyline. Once you tell Gnomon there are hills to your east, it reports when the sun clears them, not when it clears an imaginary flat horizon. The Horizon card shows both figures so you can compare.

What is the Horizon card for?

A sunrise from a valley floor is not the sunrise in the tables. Tap the card and drag across the chart to draw the hills and buildings you can actually see, with the sun's own track plotted behind them. Gnomon then works out when the sun really appears and disappears.

There is no terrain data behind this — you draw what you see. It is stored with the place, so each place keeps its own skyline.

The camera overlay is pointing the wrong way

Almost always location permission. Without it the overlay falls back to magnetic north, which differs from true north by a degree or two in the UK and considerably more elsewhere. Grant location access and it corrects itself.

If your iPhone's compass has drifted, iOS will usually prompt you to wave the phone in a figure of eight. Doing so fixes both the compass and the overlay.

Why is there no moonrise today?

Because there isn't one. Moonrise slips roughly fifty minutes each day, so a calendar day quite often contains a moonrise but no moonset, or the other way round. Gnomon reports that honestly rather than inventing a nearby time.

It says the sun does not rise

Inside the Arctic and Antarctic circles that is sometimes true. During polar night the sun stays below the horizon for weeks, and during polar day it never sets. Gnomon tells you so instead of showing a wrong time.

Accessibility

Gnomon works with VoiceOver throughout. The dial reads as a single spoken summary of where the sun is and which way shadows fall. The timeline is an adjustable element — select it and swipe up or down to move the time in quarter-hour steps.

Privacy

Gnomon collects nothing, has no accounts and makes no network calls of its own. The full privacy policy sets out the detail, including the one case where information leaves your phone.

Requirements

• iPhone running iOS 17 or later
• The camera overlay needs camera access, and location access to reference true north

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