Premium Analytics: name the selected period on the date range control

[retrofox]

Proposed changes

• The custom date range trigger names the period its range covers, where the range is one: a whole calendar month reads July 2026, a whole calendar year reads 2026. Every other range keeps the shortest form it already had.
• The exact dates move to the trigger's tooltip. #51707 removed the section header subtitle, so this is now the only place they are readable without opening the calendar.
• New formatter formatDateRangeNatural in packages/formatters. Its two collapses format a single date rather than a range, so elideRange and its CLDR probes are not involved; everything else falls through to formatDateRangeMinimal unchanged.
• New named format monthYear, derived from the site's own date_format by a withoutDay transform mirroring the existing withoutYear: F j, Y → F Y, Y-m-d → Y-m, j \d\e F \d\e Y → F \d\e Y. The weekday goes with the day, and an ordinal suffix (jS) goes with the day it trails.

Both collapses keep the year, including in the current one. This label is the only thing naming the period on the control, so a bare March would not say which March.

Both call sites of getCustomTriggerLabel move together, since the panel's measuring probe has to measure the string the trigger is actually showing.

Two decisions worth flagging:

• The tooltip appears only while the trigger holds a range of its own, staged or applied. While a preset drives the range the trigger reads Custom, and a tooltip there would put the preset's range on a control that is not showing it (WOOA7S-1936).
• No aria-label. The button already has visible text, unlike the interval glyph, so an aria-label carrying the exact range would replace the accessible name and break its correspondence with the visible label. Tooltip supplies aria-describedby, which is the right role for a complement.

A range covering two whole months (Mar 1 – Apr 30) does not collapse: it names no single period, and the spec asks for the shortest form rather than an invented one.

Related product discussion/links

• Linear: WOOA7S-2024. The collapsing rules were confirmed on the issue: the full-month example's March 30 was a typo, the year stays in the current year too, and only whole months and whole years collapse.
• Spec: Eder's 26 August recap, "Date selection" section.

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

No.

Testing instructions

• Build the dashboard: jetpack build --deps packages/premium-analytics.

• Open any analytics page.
  The steps below assume the site's date format (Settings → General → Date format) is the English default, F j, Y; the last step covers a different one.

• Open the custom range picker, select the first and last day of a past month, and Apply. The trigger reads the month and its year, for example July 2026.

• Hover or focus the trigger. Its tooltip spells the exact dates out: July 1 – 31, 2026.

• Select January 1 to December 31 of a year. The trigger reads just the year.

• Select the first to the second-to-last day of a month. The trigger falls back to the range, as before.
• Pick a rolling preset such as Last 30 days. The trigger goes back to reading Custom, with no tooltip.
• With the trigger showing a period, press Tab into the date controls toolbar and then End. Focus lands on the trigger, and the arrow keys still move along the row.
• Change Settings → General → Date format to d/m/Y and repeat the first step. The month reads 07/2026, taken from the site's own format rather than an English one.

Storybook: Packages/Premium Analytics/UI/DateRangePopover → CustomWholeMonth.

[github-actions]

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[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/date-range-natural-language branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack update/date-range-natural-language

bin/jetpack-downloader test jetpack-mu-wpcom-plugin update/date-range-natural-language

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[jp-launch-control]

Code Coverage Summary

Coverage changed in 4 files.

File	Coverage	Δ%	Δ Uncovered
projects/packages/premium-analytics/packages/formatters/src/date/format-date-range.ts	36/36 (100.00%)	0.00%	0 💚
projects/packages/premium-analytics/packages/formatters/src/date/format-date.ts	55/55 (100.00%)	0.00%	0 💚
projects/packages/premium-analytics/packages/formatters/src/date/php-format.ts	71/71 (100.00%)	0.00%	0 💚
projects/packages/premium-analytics/packages/ui/src/date-range-popover/date-range-filter.tsx	37/43 (86.05%)	0.68%	0 💚

Full summary · PHP report · JS report