function getFormattedDates (momentInstance, timezones = 'all') {
    const names = timezones === 'all' ? momentInstance.tz.names() : timezones;
    const dates = [];

    // ensure that names are equal
    names.forEach((name, i) => {
        for (let year = FROM_YEAR; year <= TO_YEAR; year++) {
            for (let month = 1; month <= 12; month++) {
                const monthFormatted = month < 10 ? '0' + month : month;
                dates.push({
                    zone: name,
                    date: `${year}-${monthFormatted}-01T00:00:00Z`,
                    formatted: momentInstance(`${year}-${monthFormatted}-01T00:00:00Z`).tz(name).format()
                });
            }
        }
    });

    return dates;
}
Iterates from FROM_YEAR to TO_YEAR
and returns formatted dates for each timezone for each month

@param momentInstance - instance of moment with timezone
@param timezones = 'all' or array of timezones you want to check
@return {Array}