fix: avoid timezone conversion that results in wrong date

Close #18

Author: javier-godoy

src/main/resources/META-INF/frontend/fc-month-calendar/fc-month-calendar.js

@@ -20,6 +20,7 @@
 import {html, PolymerElement} from '@polymer/polymer/polymer-element.js';
 
 import {MonthCalendarMixin} from './month-calendar-mixin.js'
+import {formatDate} from '../fc-year-calendar/fc-calendar-utils.js';
 
 export class FcMonthCalendarElement extends MonthCalendarMixin {
   static get is() { return 'fc-month-calendar'; }
@@ -169,7 +170,7 @@ export class FcMonthCalendarElement extends MonthCalendarMixin {
   _onSelectedDateChanged(ev) {    
     if (ev.detail.value) {
       this.dispatchEvent(new CustomEvent("date-selected", {
-        detail: {  value: ev.detail.value.toISOString().substring(0,10) }
+        detail: {  value: formatDate(ev.detail.value).substring(0,10) }
       }));
     }
   }

src/main/resources/META-INF/frontend/fc-year-calendar/fc-calendar-utils.js

@@ -0,0 +1,5 @@
+
+export function formatDate(date) {
+  var offset = date.getTimezoneOffset() * 60000;
+  return new Date(date.getTime() - offset).toISOString();
+}

src/main/resources/META-INF/frontend/fc-year-calendar/fc-year-calendar.js

@@ -23,6 +23,8 @@ import {} from '@polymer/polymer/lib/elements/dom-repeat.js';
 import {} from '@vaadin/vaadin-form-layout/src/vaadin-form-layout.js';
 import {} from '../fc-month-calendar/fc-month-calendar.js';
 
+import {formatDate} from '../fc-year-calendar/fc-calendar-utils.js';
+
 export class FcYearCalendarElement extends ThemableMixin(PolymerElement) {
   static get is() { return 'fc-year-calendar'; }
 
@@ -313,7 +315,7 @@ export class FcYearCalendarElement extends ThemableMixin(PolymerElement) {
   _onSelectedDateChanged(ev) {    
     if (ev.detail.value) {
       this.dispatchEvent(new CustomEvent("date-selected", {
-        detail: {  value: ev.detail.value.toISOString().substring(0,10) }
+        detail: {  value: formatDate(ev.detail.value).substring(0,10) }
       }));
     }
   }