core: added functionality for week format change

packages/core/src/api/settings.js

@@ -188,6 +188,18 @@ class Settings {
     this._settings.dateFormat = format;
     await this._saveSettings();
   }
+  /**
+   *
+   * @returns {"Sun" | "Mon"}
+   */
+  getWeekFormat() {
+    return this._settings.weekFromat || "Sun";
+  }
+
+  async setWeekFormat(format) {
+    this._settings.weekFromat = format;
+    await this._saveSettings();
+  }
   /**
    *
    * @returns {"12-hour" | "24-hour"}