Calendar.setup(
    {
        inputField: start_date,
        ifFormat: jscal_ifformat,
        button: trigger_start,
        firstDay: jscal_firstday,
        showsTime: showsTime,
        timeFormat: timeFormat,
        date: jscal_today,
        range: [1970, 2037],
        step: 1
    }
);
Calendar.setup(
    {
        inputField: end_date,
        ifFormat: jscal_ifformat,
        button: trigger_end,
        firstDay: jscal_firstday,
        showsTime: showsTime,
        timeFormat: timeFormat,
        date: jscal_today,
        range: [1970, 2037],
        step: 1
    }
);