How to add DatePicker in Product Image Details at admin in magento 2

At product edit page, I’m trying to add image hide date “a custom field of datepicker” so far it shows the inputbox but not calender upon clicking the box. I have override gallery.phtml and added custom input, but the script code for calender is not working.

Here’s the code:

<div class="admin__field field-display-image">
                        <div class="admin__field-control">
                            <div class="admin__field admin__field-option">
                                <label for="display-image-from-product-page-<%- data.file_id %>" class="admin__field-label vashi">
                                    <?= /* @escapeNotVerified */ __('Image Time Scope') ?>
                                </label>
                                <input type="text" class="input-text" id="example-date" style="width: auto" name="example-date" />
                            </div>
                        </div>
                    </div>

and script

<script>
  require([
    'jquery',
    'mage/translate',
    'mage/calendar'
    ], function ($, $t) {
      $('#example-date').calendar({
        alert('hi');
        changeMonth: true,
        changeYear: true,
        showButtonPanel: true,
        currentText: $t('Go Today'),
        closeText: $t('Close'),
        showWeek: true
      });
    })
</script>

All these in gallery.phtml