I can’t get a data property to not be null when I’m using axios, I don’t know whether it is because the request takes time and the value is set before it is run, I just don’t know

The property in question is responseBaseCalendarShifts

    data() {
    return {
        dateList: [],
        year: new Date().getFullYear(),
        monthNumbers: Array.from(Array(12).keys()),
        lastDateClicked: null,
        responseBaseCalendarShifts: []
    }
},

    getDates() {
        let dateArray = [];
        let currentDate = new Date(this.year, 0, 1);

        this.getBaseCalendarShifts();
        let baseCalendarShifts = this.responseBaseCalendarShifts;
        console.log(this.responseBaseCalendarShifts) // here the value is null

        while (currentDate <= new Date(this.year, 11, 31)) {
            let dateProperties = {
                id: currentDate.getFullYear() + "-" + currentDate.getMonth() + "-" + currentDate.getDate(),
                date: currentDate,
                year: currentDate.getFullYear(),
                month: currentDate.getMonth(),
                day: currentDate.getDate(),
                dayOfWeek: currentDate.getDay(),
                active: false
            };

            dateArray.push(dateProperties);

            currentDate = currentDate.addDays(1);
        }

        this.dateList = dateArray;
    },

    getBaseCalendarShifts() {
        axios.post(this.route, null, {
            params: {
                year: this.year
            }
        })
            .then(response => {
                this.responseBaseCalendarShifts = response.data;
                console.log(response.data); // here the value is correct
            })
            .catch(function (error) {
                flash('error', error);
            })
    }
},

Please help