Function addTimeblockToDailyNote

src/utils/helpers.ts:923–966

* Adds a timeblock to a daily note (creating the note if needed)

(
	app: App,
	date: string,
	timeblock: TimeBlock
)

 * Adds a timeblock to a daily note (creating the note if needed)
 */
async function addTimeblockToDailyNote(
	app: App,
	date: string,
	timeblock: TimeBlock
): Promise<void> {
	const { createDailyNote, getDailyNote, getAllDailyNotes } = await import(
		"obsidian-daily-notes-interface"
	);

	const moment = getWindowMoment(date);
	const allDailyNotes = getAllDailyNotes();
	let dailyNote = getDailyNote(moment, allDailyNotes);

	if (!dailyNote) {
		try {
			dailyNote = await createDailyNote(moment);
		} catch (error) {
			const errorMessage = error instanceof Error ? error.message : String(error);
			throw new Error(
				`Failed to create daily note: ${errorMessage}. Please check your Daily Notes plugin configuration and ensure the daily notes folder exists.`
			);
		}

		// Validate that daily note was created successfully
		if (!dailyNote) {
			throw new Error(
				"Failed to create daily note. Please check your Daily Notes plugin configuration and ensure the daily notes folder exists."
			);
		}
	}

	const content = await app.vault.read(dailyNote);
	const frontmatter =
		(extractFrontmatter(content) as DailyNoteFrontmatterWithTimeblocks | null) || {};

	if (!frontmatter.timeblocks) {
		frontmatter.timeblocks = [];
	}

	frontmatter.timeblocks.push(timeblock);

	// Save back to file
	await updateDailyNoteFrontmatter(app, dailyNote, frontmatter, content);
}

/**
 * Updates daily note frontmatter while preserving body content