common_funcs = {
    # date  as datetime
    "format_date": lambda date: "%s年%s月%s日" % (date.year - 1911, date.month, date.day),
    "y_m_d": lambda date: [date.year, date.month, date.day],
    "date_year": lambda date: date.year,
    "date_month": lambda date: date.month,
    "date_day": lambda date: date.day,
    # year as integer
    "year_minguo_to_bc": lambda year: year + 1911,
    "year_bc_to_minguo": lambda year: year - 1911,
}
