JSFiddle - React, Tailwind, and code Playground

by Alexandre Simoes

HTML

<div><span id="display"></span></div>

JavaScript

function MessagesManager() {
    var getTime = function (h, m) {
        return new Date((new Date()).setHours(h, m, 0, 0));
    };

    var responses = [
        /* days represent the day of the week. 0=Sunday, 1=Monday, ... */ 
        { days: [1, 2, 3, 4, 5], from: getTime(8, 0), to: getTime(19, 29), message: "We’re open and can see you today." }, 
        { days: [1, 2, 3, 4, 5], from: getTime(0, 0), to: getTime(7, 59), message: "We’re closed but will reopen tomorrow at 8 AM." },
        /* FILL IN THE REST */
    ];

    var isInRange = function (response, date) {
        date = date || new Date();

        return response.days.indexOf(date.getDay()) > -1 && date >= response.from && date <= response.to;
    };

    this.getMessage = function () {
        for (var i = 0; i < responses.length; i++) {
            var response = responses[i];
            if (isInRange(response)) {
                return response.message;
            }
        }

        return 'Message not found'; // you can even use this as the default closed message
    };
}

var msgs = new MessagesManager();
document.getElementById('display').innerHTML = msgs.getMessage();