A full calendar can still be an empty day. Eight hours “at work” does not mean eight hours of capacity. Energy is the variable that decides whether a block of time can hold deep work, admin, or rest—and most time trackers never record it.
This page is the practical how-to. The math behind FluxTime’s energy vector is in TimeGPT. The product surfaces (Diary, Review, heatmaps, Watch logging) are on Features.
Why hours and energy are different
Time is a clock. Energy is whether you can use that clock for the task in front of you.
Two people can log the same 90 minutes and have opposite days: one wrote in a high-focus window, the other pushed the same task through a slump and spent the next hour recovering. A start/stop timer will call those blocks equal. An energy-aware log will not.
Common “manage energy, not time” advice (sample a few times a day, score how you feel, then move hard work) is right about the diagnosis and thin on a record you can actually schedule against. A one-off mood note does not tell you when your high-energy windows usually fall.
A 7-day energy audit
You do not need a wearable to start. You need a repeatable sample.
Days 1–7, three or four times a day (morning start, late morning, mid-afternoon, evening):
- Timestamp the check-in.
- Name the block you are in (or just left).
- Score energy 1–10, or simply High / Medium / Low.
- Tag the kind of work: deep focus, meetings, admin, body, people, rest.
Rules that keep the audit honest:
- Score the last 30–60 minutes, not the whole day.
- If a block served two purposes, classify by primary intent (the same rule as in TimeGPT).
- Do not wait for a “perfect” week. A messy Tuesday is data.
At the end of seven days, look for repeatable windows, not a personality type. Many people find one reliable high-energy band (often late morning) and one reliable trough. That is enough to move one deep-work task.
How FluxTime turns the audit into a schedule
FluxTime does not ask you to maintain a separate energy spreadsheet. Interstitial check-ins in Diary already produce a time log. Categories such as Core Work versus Rest become a day-length energy vector: the essay models a day as 288 five-minute slots, then averages those vectors so high-focus work can be placed where capacity usually is.
What you do with that as a user:
- Diary — keep logging. The energy signal is a side effect of honest categories, not a second job.
- Review — read the curve and heatmap. Ask: which hours actually held Core Work, and which hours I planned for Core Work were really Rest or admin?
- Today + TimeGPT / UCEVI — let scheduling use those windows. UCEVI ranks what is worth doing (Urgent, Cost, Effort, Value, Impact). Energy ranking answers when.
- Watch and widgets — capture a check-in when the phone is away so the vector is not only “hours I sat at a Mac.”
FluxTime’s TimeGPT is this scheduler—not Nixtla’s TimeGPT, the unrelated time-series model that owns the English “TimeGPT” query.
Move one task, not your whole life
After one week:
- Pick the single highest-value task that keeps landing in a low-energy hour.
- Put it in the window Review says is actually high-energy.
- Protect that window with an event or a Today plan. Flux Pro adds smart day planning, advanced Review, Calendar, widgets, and cloud sync if you want the plan and the log on every Apple device.
Hours still matter—interstitial journaling is how FluxTime measures them. Energy is how those hours get assigned. Track both, or the calendar will keep lying.