Moved datetime from the Form plugin to Admin

themes/grav/templates/forms/fields/datetime/datetime.html.twig

@@ -0,0 +1,26 @@
+{% extends "forms/field.html.twig" %}
+
+{% set default_php_dateformat = "d-m-Y H:i" %}
+{% set php_dateformat = config.system.pages.dateformat.default ?: default_php_dateformat %}
+{% set js_dateformat = admin.dateformatToMomentJS(php_dateformat) %}
+{% set value = (value is null ? field.default : value) %}
+{% set value = (value is null ? value : value|date(php_dateformat)) %}
+
+{% block input %}
+<div class="form-input-wrapper datetime-picker-wrapper {{ field.size }}">
+    <input
+            name="{{ (scope ~ field.name)|fieldName }}"
+            value="{{ value|e('html_attr')|join(', ') }}"
+            {% block input_attributes %}
+                type="text"
+                data-grav-datetime="{{ {'format': js_dateformat} | json_encode | e('html_attr') }}"
+                {% if field.validate.min %}min="{{ (field.validate.min is null ? field.validate.min : field.validate.min|date(php_dateformat)) }}"{% endif %}
+                {% if field.validate.max %}max="{{ (field.validate.max is null ? field.validate.max : field.validate.max|date(php_dateformat)) }}"{% endif %}
+                {{ parent() }}
+            {% endblock %}
+    />
+    <span class="field-icons">
+        <i class="fa fa-fw fa-calendar"></i>
+    </span>
+</div>
+{% endblock %}