Stats: Use hour digits for hourly view X-axis labels

[dognose24]

Related to https://github.com/Automattic/red-team/issues/300

Proposed Changes

• Update the function getChartLabels for hourly chart labels in hour-digit format.

Why are these changes being made?

• Because the hourly view data is about the same date, the chart X-axis label would only need to display hour digits.

Testing Instructions

• Spin this change up with the Calypso Live branch.
• Navigate to Stats > Traffic page with the feature flag: ?flags=stats/new-date-filtering.
• Click on the chart bar to navigate to the one-day hourly view.
• Ensure the X-axis labels are all in hour-digit format.

• Navigate to Stats > Subscribers page.
• Click on any item in the Emails module to navigate to the Email Detail page.
• Toggle the chart period to Hours.
• Ensure the chart X-axis labels also show in hour-digit format and the tooltip still shows in the previous format.

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
  • For UI changes, have we tested the change in various languages (for example, ES, PT, FR, or DE)? The length of text and words vary significantly between languages.
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-126726

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-126726&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-126726&env=a8c-for-agencies

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

Sections (~6 bytes added 📈 [gzipped])

name   parsed_size           gzip_size
stats        +28 B  (+0.0%)       +6 B  (+0.0%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[annacmc]

LGTM and works as expected. Just one small spelling suggestion 😄

[matticbot]

This PR modifies the release build for the following Calypso Apps:

For info about this notification, see here: PCYsg-OT6-p2

• notifications
• odyssey-stats
• wpcom-block-editor

To test WordPress.com changes, run install-plugin.sh $pluginSlug update/stats_visits_hour_period_data_x_label on your sandbox.