Stats: Use hour digits for hourly view X-axis labels (#97118)

* Use only hour digits for chart x-axis labels for hourly view

* Format hourly view tooltips label with hour digits for the StatsEmailDetail page

* Fix typo

client/my-sites/stats/stats-email-chart-tabs/utility.js

@@ -11,7 +11,7 @@ export function formatDate( date, period ) {
 	const momentizedDate = moment( date );
 	switch ( period ) {
 		case 'hour':
-			return momentizedDate.format( 'HH:mm' );
+			return momentizedDate.format( 'MMM D' );
 		case 'day':
 			return momentizedDate.format( 'LL' );
 		default:
@@ -57,10 +57,13 @@ export const buildChartData = memoizeLast( ( activeLegend, chartTab, data, perio
 function addTooltipData( chartTab, item, period ) {
 	const tooltipData = [];
 	const label = ( () => {
+		const formattedDate = formatDate( item.data.period, period );
+
 		if ( 'hour' === period ) {
-			return item.label;
+			return `${ formattedDate } ${ item.label }`;
 		}
-		return formatDate( item.data.period, period );
+
+		return formattedDate;
 	} )();
 
 	tooltipData.push( {

client/state/stats/lists/utils.js

@@ -168,7 +168,7 @@ export function getChartLabels( unit, date, localizedDate ) {
 		const isWeekend = 'day' === unit && ( 6 === dayOfWeek || 0 === dayOfWeek );
 		const labelName = `label${ unit.charAt( 0 ).toUpperCase() + unit.slice( 1 ) }`;
 		const formats = {
-			hour: translate( 'MMM D HH:mm', {
+			hour: translate( 'HH:mm', {
 				context: 'momentjs format string (hour)',
 				comment: 'This specifies an hour for the stats x-axis label.',
 			} ),