The General Settings in WordPress enable you to change the format of the date which effects the comments.
There’s several formats to choose from and you can also enter in a custom date format.
Another way to change the date format is to use the get_comment_date filter applied in WordPress.
Here’s one way to use the filter from your child themes functions file:
Remove Comment Date
If you want to remove the date in comments, you can remove it using the Settings > General > Date Format > Custom.
You can also use PHP code like this in your functions file to return an empty string:
Both custom functions use the get_comment_date filter with the 1st parameter $d
$d. Date format. If this parameter is not specified, it will default to the format configured in your Settings > General > Date Format which uses get_option(‘date_format’)