How to set default value for configuration field with type time

Question

How can I set a default value for a field from system.xml with type time?

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Config:etc/system_file.xsd">
<system>
    <section id="my_checkout" translate="label" type="text" sortOrder="100" showInDefault="1" showInWebsite="1" showInStore="1">
        <label>Checkout</label>
        <tab>my_tab</tab>
        <resource>My_Checkout::config</resource>
        <group id="cut_off_time" translate="label" sortOrder="90" showInDefault="1" showInWebsite="1" showInStore="1">
            <label>Delivery Cut-off Time</label>
            <field id="cut_off_time_start" type="time" sortOrder="10" showInDefault="1" showInWebsite="1" showInStore="1">
                <label>Start Time</label>
            </field>
        </group>
    </section>
</system>

For field "cut_off_time_start" with type TIME.

Answer 1

Try this format:

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Store:etc/config.xsd">
    <default>
        <my_checkout>
            <cut_off_time>
                <cut_off_time_start>02,00,00</cut_off_time_start>
            </cut_off_time>
        </my_checkout>
    </default>
</config>

Answer 2

Step 1 : create file in this location for creating configuration fields –

app/code///etc/adminhtml/system.xml

<?xml version="1.0"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Config:etc/system_file.xsd">
<system>
  <section id="payment">
      <group id="wkmodule" translate="label" type="text" sortOrder="2" showInDefault="1" showInWebsite="1" showInStore="1">
          <label><![CDATA[Test Payment Module]]></label>                  
          <field id="active" translate="label" type="select" sortOrder="101" showInDefault="1" showInWebsite="1" showInStore="1">
              <label>Enabled</label>
              <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
          </field>
      </group>
  </section>

Step 2 : Create file to set default values here :

app/code///etc/config.xml

<?xml version="1.0"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Store:etc/config.xsd">
<default>
    <payment>
        <wkmodule>
            <active>0</active>
            <------>x</---->
        </wkmodule>
    </payment>
</default>

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