Premium Analytics: build the comparison menu from the applied date range

[retrofox]

Proposed changes

The Compare menu was a fixed list of three presets. It is now derived from the applied range, so presets, custom ranges, and stepped or drilled windows all resolve through the same rules.

Let n be the range's length.

Option	Offered when	Label
Previous period	always	named by the range's own length: "Previous day", "Previous 7 days", "Previous month"
Same period from last week	n ≤ 7 days	—
Same period in {month}	n ≤ 28 days	names the month it lands in
Same period in {year}	n < 365 days	names the year it lands in
No comparison	always	now last in the menu

Three rules on top:

• An option resolving to the same window as an earlier one is dropped. A 7-day range lists no last-week entry; Last 12 months lists only "Previous 12 months".
• A whole-month window steps back by months, not days. Last year compares against calendar 2024, not a Jan 2 – Dec 31 window.
• When a range change drops the active preset, the comparison falls back to the previous period instead of leaving the URL naming something the menu cannot.

Also here: previous-week is restored, so links saved before #51094 work again.

The trigger face is untouched. The vs prefix and the exact-dates tooltip are in #51820.

Related product discussion/links

• Linear: WOOA7S-2028. The full rules table and the two deliberate deviations from the prototype live in the "Comparison options as a function of the range" comment.
• Independent of Premium Analytics: turn date comparison off by default #51771, the other half of the same issue.

Does this pull request change what data or activity we track or use?

No.

Testing instructions

Build: jetpack build --deps packages/premium-analytics.

Open the Compare menu under each range and check what it offers:

Range	Expected menu
Today / Yesterday	Previous day · last week · {month} · {year}
Last 24 hours	Previous 24 hours · last week · {month} · {year}
Last 7 days	Previous 7 days · {month} · {year}
Last 30 / 90 days	Previous 30/90 days · {year}
Last month	Previous month · {year}
Last 12 months	Previous 12 months, alone
Custom, drawn in 2025	follows the length, and names 2024

"No comparison" sits last in every one of them.

Then:

• On Last month, pick "Previous month". It compares against the previous calendar month.
• On Last 7 days, pick "Same period in {month}", then switch to Last 30 days. The comparison stays active and becomes "Prev. period".
• Open a link carrying comp=1, compare_preset=previous-week and the compare dates. The week-shifted comparison renders.

One known gap, flagged by @kangzj: a link carrying compare_preset with no compare dates names the trigger but compares nothing. It predates this PR and is not specific to previous-week. #51820 fixes it.

Screen.Recording.2026-09-01.at.1.30.14.PM.mov

[github-actions]

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• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (Jetpack or WordPress.com Site Helper), and enable the update/comparison-options-from-range branch.
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[jp-launch-control]

Code Coverage Summary

Coverage changed in 6 files. Only the first 5 are listed here.

File	Coverage	Δ%	Δ Uncovered
projects/packages/premium-analytics/packages/fields/src/report-params-field/report-params-field.tsx	55/58 (94.83%)	-1.66%	1 ❤️‍🩹
projects/packages/premium-analytics/packages/datetime/src/get-comparison-range.ts	49/51 (96.08%)	1.96%	0 💚
projects/packages/premium-analytics/packages/routing/src/hooks/use-report-date-filters/build-range-patch.ts	16/16 (100.00%)	0.00%	0 💚
projects/packages/premium-analytics/packages/datetime/src/presets/comparison.ts	58/59 (98.31%)	18.31%	-1 💚
projects/packages/premium-analytics/packages/ui/src/use-comparison-date-presets/use-comparison-date-presets.ts	1/1 (100.00%)	14.29%	-1 💚

Full summary · PHP report · JS report

[kangzj]

Approving 👍 The menu follows the applied range everywhere I poked at it, the whole-month stepping lands on real calendar months, and the restored previous-week works both from the menu and from a saved link.

Blockers: none.

One note that had nowhere to sit on a line - a URL carrying comp=1&compare_preset=previous-week but no compare_from/compare_to names the trigger "Prev. week" and then renders no comparison at all, because nothing re-derives on mount. Every link the app writes carries the compare dates so in practice it's fine, and it's pre-existing and not specific to previous-week, but the deep-link bullet in the testing instructions reads a bit stronger than what actually happens. Just flagging it, not asking for anything.

Testing performed

On my local docker env (Premium Analytics dashboard in wp-admin, built from this branch), plus the package's own jest and typecheck:

#	What I checked	What I saw	Status
1	Last 30 days menu	Previous 30 days · Same period in 2025 · No comparison	✅
2	Last 7 days menu	Previous 7 days · Same period in July · Same period in 2025, no last-week entry	✅
3	Last 24 hours menu	Previous 24 hours · Same period from last week · Same period in July · Same period in 2025	✅
4	12 months menu	only Previous 12 months, and the window steps back 12 calendar months	✅
5	Single day (custom Aug 30)	Previous day · last week · July · 2025	✅
6	Custom 57-day range drawn in 2025	"Previous 57 days" and "Same period in 2024"	✅
7	Whole month Jul 1-31, pick Previous month	compares Jun 1-30, the previous calendar month	✅
8	Calendar year 2025, pick Previous 12 months	compares Jan 1 - Dec 31 2024, not a Jan 2 window	✅
9	28 vs 29 day boundary	month shift offered at 28 days, gone at 29	✅
10	"Same period in July" on 7 days, then switch to 30 days	trigger becomes "Prev. period" and compare_preset=previous-period	✅
11	Step back from calendar 2025 with the arrow	range 2024, comparison calendar 2023, preset kept	✅
12	Deep link with compare_preset=previous-week + compare dates	trigger reads "Prev. week", comparison renders	✅
13	Pick "Same period from last week" on a single day	writes previous-week and the Aug 23 window	✅
14	Custom range Aug 1-5 drawn in the calendar	compares Jul 27-31, menu follows the 5-day length	✅
15	"No comparison"	sits last, and clears comp/compare_* from the URL	✅
16	jest for packages/premium-analytics	19 suites / 280 tests pass; datetime + date-filter suites also green under UTC, America/Los_Angeles, Asia/Tokyo and Pacific/Auckland	✅
17	tsgo --noEmit and eslint on the changed files	clean	✅
18	The report-params-field staging of compare_preset	couldn't reach it - no widget on the dashboard exposes a per-widget date control, so only its unit tests cover that path	⚠️
19	Deep link with compare_preset but no compare dates	trigger names the preset, widgets show no comparison (pre-existing, same for every preset)	⚠️

Evidence

Compare menu on Last 24 hours, merge-base build vs this branch:

Nice work on this one, the labels naming the target rather than the offset makes it a lot easier to read. Thanks!

[kangzj]

This looks like the one branch of the label helper that isn't covered - a two-year custom range hits Previous %d years, and an hour-sized window hits the singular Previous hour just below. Both are reachable I think, so maybe worth a couple more rows in comparison-presets.test.ts? Not blocking.

[retrofox]

Both reachable indeed — added two rows in 929df70: a two-year custom range hitting "Previous 2 years" and a drilled single hour hitting "Previous hour". Thanks for the thorough matrix!