Magento 2 – How to Change the Date Format in Frontend

To change visible date format in date inputs You need to set proper Interface Locale in the Account Setting.

After that You will see changes on the Edit Product Page.

To change dates in frontend catalog go to: Stores > Configuration > Catalog > Catalog and find Date & Time Custom Options

There you can configure date format on store front catalog.

To change any date to 24 format in SALES menu:

override /vendor/magento/module-sales/view/adminhtml/ui_component/ xml that you need and add:<item name="dateFormat" xsi:type="string">MMM dd, YYYY, HH:mm:ss </item> for the date filed.

As an example:

  <column name="created_at" class="Magento\Ui\Component\Listing\Columns\Date">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="filter" xsi:type="string">dateRange</item>
                    <item name="component" xsi:type="string">Magento_Ui/js/grid/columns/date</item>
                    <item name="dataType" xsi:type="string">date</item>
                    <item name="label" xsi:type="string" translate="true">Created</item>
                    <item name="dateFormat" xsi:type="string">MMM dd, YYYY, HH:mm:ss </item>
                </item>
            </argument>
        </column>