Jquery UI - date range and month/year selector behave strange in Safari

Jquery UI - date range and month/year selector behave strange in Safari

Hello,

I have a datepicker restricted to some of dates in date range of July to August 2018. This works perfectly in Chrome and Mozilla, and almost in Safari.
In Chrome and Mozilla datepicker month/year selector, I have only "Jul, Aug" / "2018" selected, while in Safari there are all months and years in here. 
My client would love to have this one look same in all browsers. Is it possible to accomplish?

Thanks in advance!

Here is my code for showing this datepicker:
$(this).datepicker({
minDate: new Date("7-08-2018"),
maxDate: new Date("8-05-2018"),
dateFormat : gdlr_dfm,
numberOfMonths: [1, 2],
beforeShowDay: function(date) {
                        var datelist = ["8-7-2018", "22-7-2018", "29-7-2018", "5-8-2018"];
                        var dmy = "";
                        dmy += ("00" + date.getDate()).slice(-2) + "-";
                        dmy += ("00" + (date.getMonth() + 1)).slice(-2) + "-";
                        dmy += date.getFullYear();
                        return [$.inArray(dmy, datelist) >= 0 ? true : false, ""];
},