def event_handler(evt):
    code = evt.get_code()

    if code == lv.EVENT.VALUE_CHANGED:
        source = evt.get_target()
        date = lv.calendar_date_t()
        if source.get_pressed_date(date) == lv.RES.OK:        
            calendar.set_today_date(date.year, date.month, date.day)
            print("Clicked date: %02d.%02d.%02d"%(date.day, date.month, date.year))
                

calendar = lv.calendar(lv.scr_act())
calendar.set_size(200, 200)
calendar.align(lv.ALIGN.CENTER, 0, 20)
calendar.add_event_cb(event_handler, lv.EVENT.ALL, None)

calendar.set_today_date(2021, 02, 23)
calendar.set_showed_date(2021, 02)

# Highlight a few days
highlighted_days=[
    lv.calendar_date_t({'year':2021, 'month':2, 'day':6}),
    lv.calendar_date_t({'year':2021, 'month':2, 'day':11}),
    lv.calendar_date_t({'year':2021, 'month':2, 'day':22})
]

calendar.set_highlighted_dates(highlighted_days, len(highlighted_days))

# 2 options for header
header1 = lv.calendar_header_dropdown(lv.scr_act(),calendar)
header2 = lv.calendar_header_arrow(lv.scr_act(),calendar,25)

# Switch to switch headeres
header2.add_flag(lv.obj.FLAG.HIDDEN)
header1.clear_flag(lv.obj.FLAG.HIDDEN)

sw = lv.switch(lv.scr_act())
sw.set_pos(20,20)

def sw_cb(e):
    obj = e.get_target()
    if obj.has_state(lv.STATE.CHECKED):
        header1.add_flag(lv.obj.FLAG.HIDDEN)
        header2.clear_flag(lv.obj.FLAG.HIDDEN)
    else:
        header2.add_flag(lv.obj.FLAG.HIDDEN)
        header1.clear_flag(lv.obj.FLAG.HIDDEN)

sw.add_event_cb(sw_cb, lv.EVENT.VALUE_CHANGED, None)