I am using a theme which does not allow me to change the front end order of custom posts (I have tried every plugin and none work). Basically I have 2 filter options and those are date and title. These are really not sufficient for my needs because I want to be able to change the custom post order on a weekly basis. So, the only other way is the post publish date. I can change that of course so that the posts will be at the top of the list on a weekly basis. However, I have been reading conflicting views about this and SEO. So, is changing the post date regularly (around every month) going to be bad for SEO?
I'm not 100% sure on the effects of changing the post date on SEO. I suspect it will not be good.
Adding an order field to your custom post type (like you have with pages) isn't very hard. Here is a question on Wordpress Stack Exchange which explains it: https://wordpress.stackexchange.com/questions/65494/custom-post-type-order-field
Basically you need to add 'page-attributes' to 'supports' when registering the custom post type. for example:
register_post_type('myposttype', array( 'supports' => array('title', 'editor', 'page-attributes'), 'hierarchical' => false ));
You can then set
'orderby' => 'menu_order' on the query you want to use the custom order. The way you do this depends on how the query is set up.
This question also has some useful info on using
orderby with the page-attributes menu order: https://wordpress.stackexchange.com/questions/20722/query-menu-order-custom-post-types