Multiple Date ranges with messages

So I have unique project I need to complete... and I have to use JavaScript. Below is the script. There are some vars declared outside of function, and I didn't include that part of the code.

I'm struggling with #4 in the code below. // 4) Test on whether to show a message for a page: First, is there a date condition? If more than one date range, then choose narrowest. Then if there is more than one message, randomize.

Any help would be appreciated.

Code:

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// Start Pagelogic

function pagelogic () {       
        // Set var of element ID that we will be updating...
          var elemID = document.getElementById("messageBox");
       
        // 1) Are there any CRITICAL messages? If so, test their conditions and possibly show.
        if (critical_message != "") {
                var messageShow = critical_message;
        }
        // 2) Are we on the search results page? If so, do the search results tests - first for exact matches of the search query, then for the presence of a string in the search query.       
        else if (document.title=="Search Results") {
                // Test... will be replaced with nested if, else statements.
                var messageShow = 'This is the Search Results Page';
                setCookie("page_counter",1,tlvp_expiredays);
        }
        // 3) If not in search page, then look at page URL. If we're in a page that might have a message, do the tests on whether to show it.
        else if (document.title == 'Page 2 Test') {
                var messageShow = "This is page 2. This was set as a required message for this page.";
                setCookie("page_counter",1,tlvp_expiredays);
        }
       
        else if (document.title == 'Page 3 Test') {
                var messageShow = "This is page 3. This was set as a required message for this page.";
                setCookie("page_counter",1,tlvp_expiredays);
        }       
        // 4) Test on whether to show a message for a page: First, is there a date condition? If more than one date range, then choose narrowest. Then is there more than one message, if so use randomizer
        else if (d>=sD1 && d<=eD1) {
                var messageShow = "This message falls within the date range of 5/10 - 5/11";
                setCookie("page_counter",1,tlvp_expiredays);
        }
        else if (d>=sD2 && d<=eD2) {
                var messageShow = "This message falls within the date range of 5/10 - 5/13";
                setCookie("page_counter",1,tlvp_expiredays);
        }
       
        // 5) If no critical messages, then How recently have we shown any message? We need cookie counter for how many pages since last message. If > 5, proceed, else exit and show no message
        else if (page_count == page_count_max) {
                var r_messages = new Array(5);
                r_messages[0] = "Page Count has hit 5! 1st Random Message";
                r_messages[1] = "Page Count has hit 5! 2nd Random Message";
                r_messages[2] = "Page Count has hit 5! 3rd Random Message";
                r_messages[3] = "Page Count has hit 5! 4th Random Message";
                r_messages[4] = "Page Count has hit 5! 5th Random Message";
                var randno = Math.floor ( Math.random() * r_messages.length );
                var messageShow = r_messages[randno];
        }
       
        else {
                       
        }
       
        if (messageShow != "" && messageShow != null) {
        elemID.innerHTML = messageShow;
        elemID.style.display="block";
        }
       
        // AFTER ANY MESSAGE DISPLAY, RESET COUNTER
}

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