diff --git a/src/lib/format.ts b/src/lib/format.ts
index 943d822..c5392a9 100644
--- a/src/lib/format.ts
+++ b/src/lib/format.ts
@@ -3,6 +3,24 @@ export function formatCurrency(amount: number | string | null | undefined) {
   return new Intl.NumberFormat("en-US", { style: "currency", currency: "USD" }).format(n || 0);
 }
 
+/**
+ * Parse a date-only string ("YYYY-MM-DD") as a LOCAL date (midnight in the
+ * user's timezone). Using `new Date("2026-04-24")` parses as UTC midnight,
+ * which renders as the previous day in negative-offset timezones — that's
+ * the source of the "due date is one day earlier" bug.
+ *
+ * Returns null for falsy/invalid input. If a non date-only string or Date is
+ * passed, returns a Date built from it as-is.
+ */
+export function parseDateOnly(value: string | Date | null | undefined): Date | null {
+  if (!value) return null;
+  if (value instanceof Date) return value;
+  const m = value.match(/^(\d{4})-(\d{2})-(\d{2})$/);
+  if (m) return new Date(+m[1], +m[2] - 1, +m[3]);
+  const d = new Date(value);
+  return isNaN(d.getTime()) ? null : d;
+}
+
 export function formatDate(value: string | Date | null | undefined) {
   if (!value) return "—";
   // Date-only strings ("YYYY-MM-DD") must be rendered in UTC, otherwise