Create mod.ts

mod.ts

@@ -0,0 +1,16 @@
+
+export type DateLike = Date | number | string;
+
+export function parseDateLike(date: DateLike) {
+  if (typeof date === "string") {
+    date = new Date(date);
+  }
+
+  if (!(date instanceof Date) && typeof date !== "number") {
+    throw new TypeError(
+      `Expected "year" type to be "Date" | "number" | "string" and got ${typeof date}.`,
+    );
+  }
+
+  return date instanceof Date ? date.getUTCFullYear() : date;
+}