I needed to do this for a site I am trying to finish, so I was able to get the actual rule setup so here it is.
{ "rules_store_hours" : {
"LABEL" : "Store Hours",
"PLUGIN" : "reaction rule",
"OWNER" : "rules",
"REQUIRES" : [ "rules", "commerce_cart" ],
"ON" : { "commerce_cart_product_add" : [ ] },
"IF" : [
{ "data_is" : { "data" : [ "site:current-date" ], "op" : "\u003E", "value" : "21:00:00" } },
{ "data_is" : {
"data" : [ "site:current-date" ],
"op" : "\u003C",
"value" : "09:00:00"
}
}
],
"DO" : [
{ "drupal_message" : {
"message" : "We\u0027re sorry but we are currently closed, your item has been removed from the cart. Online ordering has been disabled until 9:00 tomorrow morning.",
"type" : "warning"
}
},
{ "commerce_cart_empty" : { "commerce_order" : [ "site:current-cart-order" ] } }
]
}
}