---
title: "Javascript Event calendar Custom Header Example | Mobiscroll"
component: "Event calendar"
framework: "JavaScript"
library_version: "6.1.5"
url: "https://demo.mobiscroll.com/javascript/eventcalendar/customizing-header"
---

# Custom Header - JavaScript Event calendar demo

Customize the Javascript event calendar header — rearrange navigation controls, toggle calendar/scheduler views or add any custom action. Plain JavaScript API.

- [Live demo](https://demo.mobiscroll.com/javascript/eventcalendar/customizing-header)
- [View code on GitHub](https://github.com/acidb/mobiscroll-demos-javascript/tree/main/src/demos/eventcalendar/calendar-view/customizing-header)
- This demo in other frameworks: [jQuery](https://demo.mobiscroll.com/jquery/eventcalendar/customizing-header.md), [Angular](https://demo.mobiscroll.com/angular/eventcalendar/customizing-header.md), [React](https://demo.mobiscroll.com/react/eventcalendar/customizing-header.md), [Vue](https://demo.mobiscroll.com/vue/eventcalendar/customizing-header.md)

## Description

You can customize how the header of the event calendar looks and how the components are arranged. Besides that you can also add custom functionality, like a segmented control that lets people switch between calendar and scheduler.

Use the [`renderHeader`](https://mobiscroll.com/docs/javascript/eventcalendar/api#renderer-renderHeader) option for passing a custom header layout. There are predefined components - shorthands if you will - that can be used to assemble the header:

- **Navigation component** - `<div mbsc-calendar-nav></div>`. Use the `.md-header-filter-controls` CSS class for custom overrides.
- **Today button** - `<button mbsc-calendar-today></button>`. Use the `.md-header-filter-today` CSS class for custom overrides.
- **Previous month button** - `<button mbsc-calendar-prev></button>`. Use the `.md-header-filter-prev` CSS class for custom overrides.
- **Next month button** - `<button mbsc-calendar-next></button>`. Use the `.md-header-filter-next` CSS class for custom overrides.

For changing the order the controls are laid out, you only need to set up the `renderHeader`. This example sets a consistent order and layout across all themes and shows a custom control at the far right end.

**Overriding the order for specific themes**

For a custom order on a theme to theme basis, you will need to use a little CSS. [Flex layout](https://css-tricks.com/snippets/css/a-guide-to-flexbox/) makes reordering easy. It's just a matter of setting the order in CSS. For material use the `.mbsc-material`, for windows the `.mbsc-windows` prefix and for iOS it is `.mbsc-ios` class. Eg.:

```
.mbsc-material .md-header-filter-prev { order: 1; }
            .mbsc-material .md-header-filter-next { order: 2; }
            .mbsc-material .md-header-filter-controls { order: 3; }
            .mbsc-material .md-header-filter-today { order: 4; }
```

**Want to add a filter to the header?** [Check out the next example →](https://demo.mobiscroll.com/javascript/eventcalendar/resource-filtering-in-header)

## What this demo shows

- A desktop month-view event calendar is shown with a custom header and a view switcher that toggles between calendar and scheduler-style layouts.
- **Header** The left side shows the currently displayed month and year. The center contains previous and next month navigation arrows with a blue `Today` button between them for jumping back to the current date. The right side contains a segmented control with a calendar icon selected by default and a list icon for switching views.
- **Event labels** Days with events display labels directly inside the month cells. Labels use different styles and colors to distinguish all-day events, multi-day, and timed events.
- **Overflow handling** The number of visible event labels depends on the available vertical space in the day cell. Additional events are moved into a popover and indicated by an `X more` label, where `X` represents the number of hidden events. Clicking it opens a popover that lists the remaining events for that day.
- **Label interaction** Hovering over or clicking an event label selects it and highlights the selected label. This is tru in both views, event calendar month view and the scheduler week view.
- **Day cell states** Hovering a day cell highlights the day number with a gray background, while clicking the empty part of the cell selects the day and highlights the day number with a blue background.
- **Month navigation** The month can be changed by clicking and dragging the calendar left or right.
- **Scheduler view** Selecting the list option from the segmented control switches the layout to a weekly scheduler view.
- **Scheduler view** The weekly scheduler shows the days of the week at the top, an all-day section for all-day events, and a 24-hour time grid for timed events.
- **Scheduler view** The current time is marked with a blue line in the time grid.
- **Scheduler view** The time grid can be scrolled vertically with the mouse wheel while the header stays sticky.

## Best for

- **Calendar and schedule switching** Interfaces where users need to move between a month overview and a more detailed weekly schedule from the same header control.
- **Desktop planning tools** Scheduling and planning screens designed for desktop use, where a full month grid and richer header controls fit naturally.
- **Operational scheduling** Team, resource, booking, or internal planning tools where users switch between high-level monthly planning and time-precise weekly scheduling.

## API used in this demo

- [`theme`](https://mobiscroll.com/docs/javascript/eventcalendar/api#opt-theme) - option
- [`themeVariant`](https://mobiscroll.com/docs/javascript/eventcalendar/api#opt-themeVariant) - option
- [`clickToCreate`](https://mobiscroll.com/docs/javascript/eventcalendar/api#opt-clickToCreate) - option
- [`dragToCreate`](https://mobiscroll.com/docs/javascript/eventcalendar/api#opt-dragToCreate) - option
- [`dragToMove`](https://mobiscroll.com/docs/javascript/eventcalendar/api#opt-dragToMove) - option
- [`dragToResize`](https://mobiscroll.com/docs/javascript/eventcalendar/api#opt-dragToResize) - option
- [`eventDelete`](https://mobiscroll.com/docs/javascript/eventcalendar/api#opt-eventDelete) - option
- [`view`](https://mobiscroll.com/docs/javascript/eventcalendar/api#opt-view) - option
- [`labels`](https://mobiscroll.com/docs/javascript/eventcalendar/api#opt-labels) - option
- [`onSelectedDateChange`](https://mobiscroll.com/docs/javascript/eventcalendar/api#event-onSelectedDateChange) - event
- [`renderHeader`](https://mobiscroll.com/docs/javascript/eventcalendar/api#renderer-renderHeader) - renderer
- [`setEvents`](https://mobiscroll.com/docs/javascript/eventcalendar/api#method-setEvents) - method
- [`navigate`](https://mobiscroll.com/docs/javascript/eventcalendar/api#method-navigate) - method
- [`setOptions`](https://mobiscroll.com/docs/javascript/eventcalendar/api#method-setOptions) - method

## Code

### JS

```js
mobiscroll.setOptions({
  theme: 'ios',
  themeVariant: 'light'
});

var currentDate = new Date();
var view = 'calendar';
var calendar = mobiscroll.eventcalendar('#demo-custom-header', {
  clickToCreate: true,
  dragToCreate: true,
  dragToMove: true,
  dragToResize: true,
  eventDelete: true,
  view: {
    calendar: {
      labels: true,
    },
  },
  onSelectedDateChange: function (args) {
    currentDate = args.date;
  },
  renderHeader: function () {
    return (
      '<div mbsc-calendar-nav class="md-custom-header-nav"></div>' +
      '<div class="md-custom-header-controls">' +
      '<button id="nav-to-prev-page" mbsc-button data-variant="flat" data-icon="material-arrow-back" class="md-custom-header-button"></button>' +
      '<div mbsc-calendar-today class="md-custom-header-today"></div>' +
      '<button id="nav-to-next-page" mbsc-button data-variant="flat" data-icon="material-arrow-forward" class="md-custom-header-button"></button>' +
      '</div>' +
      '<div class="md-custom-header-view">' +
      '<label><input data-icon="calendar" mbsc-segmented type="radio" name="view" value="calendar" class="md-view-change" checked></label>' +
      '<label><input data-icon="material-list" mbsc-segmented type="radio" name="view" value="schedule" class="md-view-change"></label>' +
      '</div>'
    );
  },
});

mobiscroll.getJson(
  'https://trial.mobiscroll.com/events/?vers=5',
  function (events) {
    calendar.setEvents(events);
  },
  'jsonp',
);

function getFirstDayOfWeek(d, prev) {
  var day = d.getDay();
  var diff = d.getDate() - day + (prev ? -7 : 7);
  return new Date(d.setDate(diff));
}

function navigatePage(prev) {
  if (view == 'calendar') {
    var prevNextPage = new Date(currentDate.getFullYear(), currentDate.getMonth() + (prev ? -1 : 1), 1);
    calendar.navigate(prevNextPage);
    currentDate = prevNextPage;
  } else {
    var prevNextSunday = getFirstDayOfWeek(currentDate, prev);
    calendar.navigate(prevNextSunday);
    currentDate = prevNextSunday;
  }
}

document.querySelectorAll('.md-view-change').forEach(function (elm) {
  elm.addEventListener('change', function (ev) {
    switch (ev.target.value) {
      case 'calendar':
        calendar.setOptions({
          view: {
            calendar: { labels: true },
          },
        });
        view = 'calendar';
        break;
      case 'schedule':
        calendar.setOptions({
          view: {
            scheduler: { type: 'week' },
          },
        });
        view = 'schedule';
        break;
    }
  });
});

document.getElementById('nav-to-prev-page').addEventListener('click', function () {
  navigatePage(true);
});

document.getElementById('nav-to-next-page').addEventListener('click', function () {
  navigatePage(false);
});
```

### HTML

```html
<div id="demo-custom-header" class="md-custom-header"></div>
```

### CSS

```css
.md-custom-header-controls {
    display: flex;
    flex: 1 0 auto;
    justify-content: center;
    align-items: center;
}

.md-custom-header-nav,
.md-custom-header-view {
    width: 180px;
}

.md-custom-header-button.mbsc-button {
    font-size: 20px;
    height: auto;
    padding: 0;
    margin: 0;
}

.md-custom-header .mbsc-segmented {
    width: 110px;
    float: right;
    margin-top: 0;
    margin-bottom: 0;
}

.md-custom-header .mbsc-material.mbsc-segmented,
.md-custom-header .mbsc-windows.mbsc-segmented {
    padding: 0;
}

.md-custom-header .mbsc-segmented .mbsc-segmented-button {
    font-size: 20px;
    height: 32px;
    padding: 0;
}
```

## Implementation notes

- Define two view configs toggled by a state variable: calendar uses `{ calendar: { labels: true } }`; schedule uses `{ scheduler: { type: 'week' } }`.
- Use `renderHeader` (Angular: `headerTemplate`, Vue: `header` slot) to build a fully custom header with three zones:
  - Left: `CalendarNav` for the month/year title
  - Center: two flat icon `Button` components (`material-arrow-back` and `material-arrow-forward`) flanking `CalendarToday` - these replace the built-in `CalendarPrev`/`CalendarNext`
  - Right: an icon-only `SegmentedGroup` with a `calendar` icon and a `material-list` icon for switching between views
- Track the currently displayed date in a `selectedDate` state variable, kept in sync via `onSelectedDateChange`. The custom prev/next buttons call a `navigatePage()` helper that computes the target date based on the active view: in calendar view, it adds or subtracts one month; in schedule view, it adds or subtracts one week. Update `selectedDate` with the result to drive navigation. JS/jQuery: call `inst.navigate(date)` instead of updating a bound prop.
- Load events from a remote endpoint using `getJson` and assign them to `data`; for the imperative API, call `inst.setEvents(events)` in the callback.

## Run it in your project

1. If not signed up yet, or don't own a license, you can [start a free trial](https://mobiscroll.com/starttrial).

2. Clone the repository:

   ```
   git clone https://github.com/acidb/mobiscroll-demos-javascript.git
   ```

3. If not installed yet, install the Mobiscroll CLI from NPM:

   ```
   npm install -g @mobiscroll/cli
   ```

4. Config Mobiscroll - open a terminal window in the root directory and run:

   ```
   mobiscroll config javascript
   ```

5. Install dependencies - open a terminal window in the root directory and run:

   ```
   npm install
   ```

6. Run the project:

   ```
   npm run dev
   ```

On a trial, add `--trial` to the config command: `mobiscroll config javascript --trial`.

Running a demo locally requires a Mobiscroll trial or a license; setup is per framework at https://mobiscroll.com/docs/javascript/getting-started/installation

## Related demos

- Previous: [Event Popover](https://demo.mobiscroll.com/javascript/eventcalendar/customize-event-popover.md) - Customize how events appear in the day popover of a Javascript event calendar — use full custom layouts or add fields like assignee, location, and participants.
- Next: [Custom Event Tooltip](https://demo.mobiscroll.com/javascript/eventcalendar/custom-event-tooltip.md) - Add custom hover tooltips to a Javascript event calendar — show appointment details, status, location, and confirm or delete actions to each event.