Fix date issues

src/lib/components/wizard/StepGenerate.svelte

@@ -201,52 +201,22 @@
 		});
 	}
 
-	// Format a date-like string into "DD MM YY" with basic heuristics for common inputs
+	// Format a YYYY-MM-DD string into "DD   MM   YY"
 	function formatDateDDMMYY(value: string): string {
 		if (!value) return '';
 		const trimmed = value.trim();
 
-		// ISO: YYYY-MM-DD or YYYY/MM/DD
-		let m = trimmed.match(/^(\d{4})[\/\-](\d{2})[\/\-](\d{2})$/);
-		if (m) {
-			const [, y, mo, d] = m;
-			return `${d}   ${mo}   ${y.slice(-2)}`;
-		}
-
-		// DMY with separators: DD.MM.YYYY or DD/MM/YYYY or DD-MM-YYYY
-		m = trimmed.match(/^(\d{2})[.\/-](\d{2})[.\/-](\d{4})$/);
-		if (m) {
-			const [, d, mo, y] = m;
-			return `${d}   ${mo}   ${y.slice(-2)}`;
-		}
-
-		// DMY two-digit year: DD.MM.YY or DD/MM/YY or DD-MM-YY
-		m = trimmed.match(/^(\d{2})[.\/-](\d{2})[.\/-](\d{2})$/);
-		if (m) {
-			const [, d, mo, y2] = m;
-			return `${d}   ${mo}  ${y2}`;
-		}
-
-		// Try native Date parsing as a last resort
-		const parsed = new Date(trimmed);
-		if (!isNaN(parsed.getTime())) {
-			const dd = String(parsed.getDate()).padStart(2, '0');
-			const mm = String(parsed.getMonth() + 1).padStart(2, '0');
-			const yy = String(parsed.getFullYear()).slice(-2);
-			return `${dd}   ${mm}   ${yy}`;
-		}
-
-		// Handle plain numeric serials (e.g., Google/Excel serial days since 1899-12-30)
-		if (/^\d{5,}$/.test(trimmed)) {
-			const days = parseInt(trimmed, 10);
-			const base = new Date(Date.UTC(1899, 11, 30));
-			base.setUTCDate(base.getUTCDate() + days);
-			const dd = String(base.getUTCDate()).padStart(2, '0');
-			const mm = String(base.getUTCMonth() + 1).padStart(2, '0');
-			const yy = String(base.getUTCFullYear()).slice(-2);
-			return `${dd}   ${mm}   ${yy}`;
+		// Expects YYYY-MM-DD and splits it
+		const parts = trimmed.split('-');
+		if (parts.length === 3) {
+			const [y, mo, d] = parts;
+			if (y.length === 4 && mo.length === 2 && d.length === 2) {
+				return `${d}   ${mo}   ${y.slice(-2)}`;
+			}
 		}
 
+		// Fallback for any other format that might slip through
+		console.warn(`Unexpected date format received in formatDateDDMMYY: "${trimmed}"`);
 		return trimmed;
 	}
 

src/lib/components/wizard/StepRowFilter.svelte

@@ -10,6 +10,7 @@
 	import { v4 as uuid } from 'uuid';
 	import Navigator from './subcomponents/Navigator.svelte';
 	import { onMount } from 'svelte';
+	import { parseAndFormatDate } from '$lib/utils/date';
 
 	let isLoading = $state(true);
 	let error = $state<string | null>(null);
@@ -53,6 +54,9 @@
 					const name = mapping.name !== -1 ? row[mapping.name] || '' : '';
 					const pictureUrl = mapping.pictureUrl !== -1 ? row[mapping.pictureUrl] || '' : '';
 
+					const birthdayRaw = mapping.birthday !== -1 ? row[mapping.birthday] : '';
+					const birthday = parseAndFormatDate(birthdayRaw);
+
 					if (!name && !pictureUrl) {
 						return null; // Skip entirely empty rows
 					}
@@ -68,7 +72,7 @@
 						id: uuid(),
 						name,
 						nationality: mapping.nationality !== -1 ? row[mapping.nationality] || '' : '',
-						birthday: mapping.birthday !== -1 ? row[mapping.birthday] || '' : '',
+						birthday,
 						pictureUrl,
 						alreadyPrinted,
 						_rowIndex: index + 1,

src/lib/utils/date.ts

@@ -0,0 +1,68 @@
+/**
+ * Parses a date string from various common formats and returns it in YYYY-MM-DD format.
+ * Handles ISO (YYYY-MM-DD), European (DD.MM.YYYY), and US (MM/DD/YYYY) formats,
+ * as well as Excel-style serial numbers.
+ * @param value The date string to parse.
+ * @returns The formatted date string or the original value if parsing fails.
+ */
+export function parseAndFormatDate(value: string | number | undefined): string {
+	if (value === undefined || value === null || value === '') return '';
+
+	const trimmed = value.toString().trim();
+	if (!trimmed) return '';
+
+	let date: Date | null = null;
+
+	// 1. Try direct parsing (handles ISO 8601 like YYYY-MM-DD)
+	const directParse = new Date(trimmed);
+	if (!isNaN(directParse.getTime()) && trimmed.match(/^\d{4}/)) {
+		date = directParse;
+	}
+
+	// 2. Regex for MM/DD/YYYY or MM.DD.YYYY or MM-DD-YYYY (common in Google Forms)
+	if (!date) {
+		const mdyMatch = trimmed.match(/^(\d{1,2})[./-](\d{1,2})[./-](\d{2,4})$/);
+		if (mdyMatch) {
+			const [, m, d, y] = mdyMatch;
+			// Basic validation to avoid mixing up DMY and MDY for ambiguous dates like 01/02/2023
+			// If the first part is > 12, it's likely a day (DMY), so we'll let the next block handle it.
+			if (parseInt(m) <= 12) {
+				const year = y.length === 2 ? parseInt(`20${y}`) : parseInt(y);
+				date = new Date(year, parseInt(m) - 1, parseInt(d));
+			}
+		}
+	}
+
+	// 3. Regex for DD/MM/YYYY or DD.MM.YYYY or DD-MM-YYYY
+	if (!date) {
+		const dmyMatch = trimmed.match(/^(\d{1,2})[./-](\d{1,2})[./-](\d{2,4})$/);
+		if (dmyMatch) {
+			const [, d, m, y] = dmyMatch;
+			const year = y.length === 2 ? parseInt(`20${y}`) : parseInt(y);
+			// Month is 0-indexed in JS
+			date = new Date(year, parseInt(m) - 1, parseInt(d));
+		}
+	}
+
+	// 4. Handle Excel serial date number (days since 1900-01-01, with Excel's leap year bug)
+	if (!date && /^\d{5}$/.test(trimmed)) {
+		const serial = parseInt(trimmed, 10);
+		// Excel's epoch starts on day 1, which it considers 1900-01-01.
+		// JS Date epoch is 1970-01-01.
+		// Days between 1900-01-01 and 1970-01-01 is 25569.
+		// Excel incorrectly thinks 1900 was a leap year, so we subtract 1 for dates after Feb 1900.
+		const excelEpochDiff = serial > 60 ? 25567 : 25568;
+		const utcMilliseconds = (serial - excelEpochDiff) * 86400 * 1000;
+		date = new Date(utcMilliseconds);
+	}
+
+	// If we have a valid date, format it. Otherwise, return original.
+	if (date && !isNaN(date.getTime())) {
+		const year = date.getFullYear();
+		const month = (date.getMonth() + 1).toString().padStart(2, '0');
+		const day = date.getDate().toString().padStart(2, '0');
+		return `${year}-${month}-${day}`;
+	}
+
+	return trimmed; // Fallback
+}