WINTER ARC · FIELD GUIDE
How to plan a 90-day Winter Arc
Content reviewed
A useful arc is a limited period with commitments you can recognize. This tracker gives you exactly 90 calendar dates and one to five daily rules. It does not promise a transformation, prescribe a health routine, or require a particular season.
What does “Winter Arc” mean here?
Under Armour and Gymshark describe the social trend as a period of goal-setting before the new year. Their descriptions provide context, not a universal calendar standard. In this tool you choose any start date. The end is start + 89 days because the first day is already day 1.
Worked date example: start October 1, 2026 → day 30 October 30 → day 60 November 29 → day 90 December 29. October 1 through December 31 is 92 days, so “three months” is not a substitute for the 90-day calculation.
Leap days count normally. February 1, 2028 ends April 30, 2028. Daylight-saving changes do not add or remove a calendar day. Today follows the device’s local date; saved labels stay the same when you travel. Check your device clock if a day seems locked early or late.
1. Write a rule that can be checked
Use an action, a small boundary and a recognizable finish. Start with one rule if five would make returning harder. The maximum of five is a product limit to keep the daily screen compact, not a scientifically established optimum.
| Vague or brittle | A clearer example | What you can check |
|---|---|---|
| “Be more creative” | Write one paragraph | One paragraph exists |
| “Never get distracted” | Put my phone away for one focus session | One session had that boundary |
| “Read everything on my list” | Read ten pages of my chosen book | Ten pages were read |
These are editable examples. Choose actions suitable for your circumstances. Avoid a rule that depends entirely on another person or on an outcome you cannot control. Do not use this tracker to set extreme exercise, food or sleep restrictions.
2. Decide what a missed day means before it happens
A missed commitment and a forgotten check-in are different. If you did the action but forgot to record it, select the past date and check it honestly. If you know you did not do it, choose Marked missed and continue today. Leave uncertain dates unrecorded; planned rest is a separate explicit state. The calendar does not restart itself, and empty days remain visible.
Use Complete day only after doing every rule. Uncheck a mistaken box at any time on an eligible date. Undo reverses up to 20 saved actions in the current tab; reloading or another tab’s update clears that undo list. You can still correct past checkboxes after reload.
3. Review the week, not your worth
The top percentage is complete days divided by 90. A complete day needs every rule. The recent review uses the last seven reached dates within this arc, including today; before seven days have elapsed it uses only those reached. Future days never enter that denominator.
Example: on day 4, completing a reading rule on three days gives that rule 3/4 in the review. If all rules were complete on two days, the main progress is 2/90. Those figures answer different questions and are not inconsistent.
Planned rest is excluded from per-rule review denominators; marked missed and unrecorded dates stay included. Old checkmarks on rest or missed dates remain saved but do not count as completion. The dashboard avoids a streak-pressure prompt. Use the weekly and phase review to save one adjustment based on your notes.
4. Keep the history understandable
Edit wording is for correcting a label or clarifying the same action. It applies to the whole arc, including past days. Changing “read ten pages” to “write one page” would rewrite the meaning of old checks; export and start a new arc instead.
Daily notes are optional and limited to 500 characters. Save explicitly. Unsaved note drafts survive date and language switches in this tab but are not in backups. Leaving the page can discard them after a browser warning.
Common questions
Must I start in October?
No. Pick any supported start date. This is a fixed 90-day tracker, and it does not inspect weather or your location.
Can I change the start date afterward?
The active arc’s start date is fixed to protect date history. Export your record and start a new arc if the period needs to change.
Do I need to complete all five rules?
You can choose one to five rules. A fully complete day means all the rules you chose, even if you chose only one.
Can I use English and Chinese together?
Yes. Interface language changes labels and date display. Your own rule text is left exactly as written.
Context and method
This guide’s date examples and behavior descriptions are original and checked against this prototype’s date and persistence tests. Trend context: Under Armour’s Winter Arc overview and Gymshark’s October 2024 explanation. Reviewed October 5, 2026. No claim is made that 90 days guarantees a habit.