A smart thermostat is only smart while nothing changes. The moment it does — you leave early, work from home, fly out for a fortnight — most apps make you choose between two bad options: fight the automation by holding a manual temperature, or tear up the schedule and rebuild it later.

The design goal was a control surface where the routine and the interruption are first-class citizens side by side. You should be able to set the week once, drop in a one-off change when life needs it, and trust that the plan resumes on its own — no cleanup, no forgotten holds silently costing energy.

Home is the live dashboard for the selected device (here, ECY - STAT). It answers the three questions someone actually walks in with — what is it right now, is the system even on, and can I change it — before anything else. Indoor temperature and the master power sit at the top, with outdoor weather, humidity, and the last sync time as supporting context.

Switching to Heatproves the panel isn't static art: the slider warms to amber, the set point jumps to the heating target, and a fan-speedcard slides in with its own slider and an Auto option. The controls that matter for the current mode appear; the ones that don't stay out of the way.

Underneath the panel sit comfort profiles— the named presets the whole system leans on. Rather than remember that “home” means 27° heating / 22° cooling at 40% fan, you set that once and every other surface — occupancy, schedule, exceptions — just refers to Home, Away, or Vacation by name.

Opening any profile reveals the full editor: separate Heating and Cooling blocks, each with a temperature set point and a fan-speed slider that can fall back to Auto. Vacation reframes the same controls as Heat Preference and Cool Preference— a small wording shift that signals “keep it safe and minimal” rather than “keep it comfortable.”

The scheduleis where the routine lives. A week strip sits above a vertical timeline of the day's comfort blocks — Home at 8:00 AM, Away at 9:00 AM — each showing the heating and cooling targets it will hold. It reads like a calendar, not a config screen.

Adding a block is deliberately small: the Add Activitysheet asks only three things — which comfort profile, which day(s), and a start time. A repeating schedule block doesn't need an end time; the next block is the end. Add a midday Homeblock and the timeline becomes Home → Away → Home, the last one running “Until Next Day.”

Exceptionsare the answer to “today is different.” The very same Add Activity sheet has a Type toggle at the top — flip it from Schedule to Exception and the day-of-week picker is replaced by an explicit start and end date-time. One form, two jobs: the recurring plan and the one-off override.

A holiday is just a long exception, so it's built from the same parts. Pick the Vacation profile, then set a date range that can span months — a dedicated calendar makes selecting “2 Jan to 10 Jan” a single highlighted sweep rather than two fiddly pickers.

When it's active, vacation is unmistakable: a purple block on the timeline, running its minimal-energy targets “Until Next Day” across the whole trip. And because it's an exception with an end date, the normal week snaps back the moment you're home — no stale holiday hold quietly running for another fortnight.

Settings stays intentionally light — profile, theme, and an activity logthat records what the system did and who changed what, plus the essentials of help and sign-out. For a device that mostly runs itself, the log is the trust anchor: it answers “why is it 27° right now?” after the fact.

What held it together

The through-line was one form and one vocabulary doing double duty. Comfort profiles name the “how,” the schedule places them in time, and the exact same Add Activity sheet — with a single Type toggle — produces both the recurring plan and the one-off override. That reuse is what let a genuinely capable automation surface stay small enough to run from a phone in a hallway.

And every override is designed to be temporary by construction. Exceptions carry an end; the schedule is always visible beneath them; the routine resumes on its own. The app trusts the plan, and gives people a safe, legible way to step outside it when real life asks.