code refactor

src/lib/datetime.ts

@@ -143,11 +143,11 @@ export function getTimezoneOffsetMinutes(timezone?: string): number {
     }
 }
 
-export function getBrowserTimezoneOffset() {
+export function getBrowserTimezoneOffset(): string {
     return getUtcOffsetByUtcOffsetMinutes(getBrowserTimezoneOffsetMinutes());
 }
 
-export function getBrowserTimezoneOffsetMinutes() {
+export function getBrowserTimezoneOffsetMinutes(): number {
     return -new Date().getTimezoneOffset();
 }
 

src/lib/ui/mobile.ts

@@ -84,7 +84,7 @@ export function showLoading(delayConditionFunc?: () => boolean, delayMills?: num
     });
 }
 
-export function hideLoading() {
+export function hideLoading(): void {
     f7ready((f7) => {
         return f7.preloader.hide();
     });