const holidaysManual = [
        "2022-01-03",
        "2022-01-07"
      ]

// ======================================

fetch("https://freshservicecounter.ringteam.com/getholidays").then(res => {
        return res.json()
      }).then(holidays => {
        const holidaysAll = holidays.concat(holidaysManual)
        console.log(holidaysAll)
        dateList.forEach(dateElem => {
          jQuery(dateElem).datepicker("option", {
            beforeShowDay: function(dateRaw) {
              dateRaw.setHours(dateRaw.getHours() + 3)
              const dateIso = dateRaw.toISOString().split("T")[0]
              return [!holidaysAll.includes(dateIso), ""]
            }
          })
        })
      })