feat: add $(internal:date_monthname) variable #3819

Author: Julusian

companion/lib/Internal/Time.ts

@@ -55,6 +55,10 @@ export class InternalTime extends EventEmitter<InternalModuleFragmentEvents> imp
 				description: 'Date (Month)',
 				name: 'date_m',
 			},
+			{
+				description: 'Date (Month name)',
+				name: 'date_monthname',
+			},
 			{
 				description: 'Date (Day)',
 				name: 'date_d',
@@ -147,6 +151,7 @@ export class InternalTime extends EventEmitter<InternalModuleFragmentEvents> imp
 			date_iso: `${year}-${month}-${day}`,
 			date_y: year,
 			date_m: month,
+			date_monthname: now.toLocaleString(undefined, { month: 'long', timeZone: effectiveTz }),
 			date_d: day,
 			date_dow: parts.weekday,
 			date_weekday: now.toLocaleString(undefined, { weekday: 'long', timeZone: effectiveTz }),

companion/test/Internal/Time.test.ts

@@ -41,11 +41,12 @@ describe('InternalTime', () => {
 			const defs = time.getVariableDefinitions()
 			const names = defs.map((d) => d.name)
 
-			expect(defs).toHaveLength(17)
+			expect(defs).toHaveLength(18)
 			expect(names).toEqual([
 				'date_iso',
 				'date_y',
 				'date_m',
+				'date_monthname',
 				'date_d',
 				'date_dow',
 				'date_weekday',
@@ -182,6 +183,28 @@ describe('InternalTime', () => {
 			})
 		})
 
+		test('emits the month name in the configured timezone', () => {
+			// Just after midnight UTC on 1 July: still June in New York, already July in Tokyo
+			const now = new Date('2024-07-01T01:30:00Z')
+			const config = { timezone: 'America/New_York' }
+
+			vi.setSystemTime(now)
+			const time = new InternalTime(mockUserConfig(config))
+			const setVariables = vi.fn<(values: VariableValues) => void>()
+			time.on('setVariables', setVariables)
+
+			// Compare against the host locale's names, so the assertion is locale-independent
+			const monthName = (m: number) =>
+				new Date(Date.UTC(2024, m, 15)).toLocaleString(undefined, { month: 'long', timeZone: 'UTC' })
+
+			time.updateVariables()
+			expect(lastValues(setVariables).date_monthname).toBe(monthName(5))
+
+			config.timezone = 'Asia/Tokyo'
+			time.updateVariables()
+			expect(lastValues(setVariables).date_monthname).toBe(monthName(6))
+		})
+
 		test('exposes the resolved system timezone when none is configured', () => {
 			const { time, setVariables } = createTime(new Date('2024-06-15T01:30:00Z'))
 			time.updateVariables()